Czech Journal of Food Sciences, 2009 (vol. 27), Special Issue 1

Lipids: Their Role in the Formation of Endogenous Antioxidants during Food Processing

R. Zamora, F. J. Hidalgo

Czech J. Food Sci., 2009, 27(10):S1-S3 | DOI: 10.17221/633-CJFS  

Lipids are important food nutrients and they also carry out other functions such as to be carriers of aromatic substances or to influence food texture, for example. However, polyunsaturated acids are also easily oxidised. In fact, oxidative rancidity of edible oils is a serious problem in the food industry. As an alternative to the use of synthetic antioxidants, the generation of endogenous antioxidants by carbonyl-amine reactions can be employed to increase food stability. These reactions are widely accepted to be produced as a consequence of Maillard reactions between carbohydrates and amino compounds. However, the contribution of lipid-derived carbonyl...

Determination of Lactoferrin in Goat Milk by HPLC Method

M. Dračková, I. Borkovcová, B. Janštová, M. Naiserová, H. Přidalová, P. Navrátilová, L. Vorlová

Czech J. Food Sci., 2009, 27(10):S102-S104 | DOI: 10.17221/944-CJFS  

The aim of this study was the determination of lactoferrin in goat milk using HPLC method. Milk samples were collected at a goat farm in the South Moravia Region, the Czech Republic. It were established bulk tank samples of raw milk (n = 24) and pasteurised milk (nn = 27) that were collected during lactation. Lactoferrin contents were analysed by reverse phase high-performance liquid chromatography (RP-HPLC) with diode-array detector PDA 2996. Detection was carried out at the wavelength 205 nm. The average concentration of lactoferrin in goat milk was 120 ± 18 μg/ml. The lactoferrin content was increasing within the lactation...

A Comparative Study of the Analysis of Free Fatty Acids in Cheeses (Cow's, Ewe's and Goat's) with Different Ripening Times using NIRS: Intact Samples and Fat Extracts

I. González-Martín, J. M Hernández-Hierro, I. Revilla, A. Vivar-Quintana, R. Morón-Sancho, J. Salvador-Esteban

Czech J. Food Sci., 2009, 27(10):S105 | DOI: 10.17221/964-CJFS

Lipolysis is of great importance in the development of the aroma and flavour of cheese and one of the usual ways of measuring it is to assess variations in fatty acids. The relative proportions of fatty acids in milk fat depend on the animal species, the stage of lactation and feed regime, the ripening time and the climatic conditions and microbiological quality of the milk. GC-MS is the reference method for the determination of fatty acids in cheeses, but the technique involves long analysis times.

Seasonal Evolution of Hydrophilic and Hydrophobic Peptide Contents in Cheeses Made from Ewe's Goat's or Cow's Milk

A. M. Vivar-Quintana, M.A. Blanco López, I. Revilla, I. González-Martín, J. M. Hernández-Hierro, C. González-Pérez

Czech J. Food Sci., 2009, 27(10):S106-S108 | DOI: 10.17221/950-CJFS  

Proteolysis is the principal and most complex biochemical event occurring during the maturation of the majority of ripened cheese varieties. In addition to softening the cheese body, proteolysis influences the development of cheese flavour via the formation of amino acid and peptides which make a direct contribution to flavour. Goat, cow and sheep cheeses have been elaborated with raw milk and calf rennet. The extent of proteolysis was monitored over six months of ripening and means of HPLC peptide profile analysis. The influence of season on the changes in hydrophobic and hydrophilic peptides and the HO/HI ratio during the ripening of the cheeses...

Effect of Pulsed Electric Fields on the Main Chemical Components of Liquid Egg and Stability at 4°C

R. Marco-Molés, I. Pérez-Munuera, A. Quiles, I. Hernando

Czech J. Food Sci., 2009, 27(10):S109-S112 | DOI: 10.17221/622-CJFS  

The effect of PEF on the whole liquid egg components, proteins and lipids, and the microstructure were studied and compared with pasteurisation. The effect of the refrigerated storage one week after the treatments was too studied. After all the treatments, only pasteurised samples showed water-soluble protein values significantly lower than the control and PEF treated samples, even after refrigeration. This could be related to the reinforcement of protein-protein interactions generated by the partial denaturalisation of proteins, observed by Cryo-SEM. Moreover, a water-soluble protein decrease was detected in the control and PEF treated samples after...

Determination of the Mineral Composition (Ca, P, Mg, K, Na) in Cheeses (Cow's, Ewe's and Goat's) with Different Ripening Times using Near Infrared Spectroscopy (NIRs) with a Fibre-Optic Probe

I. González-Martín, J. M Hernández-Hierro, I. Revilla, A. Vivar-Quintana, I. Lobos-Ortega, C. González-Pérez

Czech J. Food Sci., 2009, 27(10):S113 | DOI: 10.17221/1081-CJFS

In the present work we study the use of NIRS technology together with the use of a remote reflectance fibre-optic probe (with a 5 cm × 5 cm quartz window) for the determination of mineral composition (Ca, P, Mg, K, Na) in 227 samples of cheeses elaborated with 16 varying mixtures of milk from cows, ewes and goats with different ripening times over 6 months. The NIR spectra were recorded in reflectance mode, applying the fibre-optic probe directly onto the cheese simple, with no simple preparation or manipulation.

Changes in the Mineral Content in Cheeses of Different Compositions during 6 Months of Ripening

I. González-Martín, J. M. Hernández-Hierro, I. Revilla, A. Vivar-Quintana, I. Lobos-Ortega, C. González-Pérez

Czech J. Food Sci., 2009, 27(10):S114-S118 | DOI: 10.17221/1086-CJFS  

The mineral content of cheese depends on the origin of the milk (cow, ewe, goat) and its ripening. In this work the effect of different factors on the mineral composition and the correlation between minerals (Ca, Fe, Mg, K, Na, and Zn) and the type of milk used are studied. The One-Way ANOVA procedure revealed that the effect of cow's milk was statistically significant on Fe, K, P, and Zn; goat's milk was statistically significant for Fe and Mg, and ewe's milk was statistically significant for K. The effect of the ripening time was statistically significant in all cases, except for Zn; the effect of the season was statistically significant for K, Mg...

Study on Interaction between Broad Bean Phenolic Compounds and Proteins using Fluorescence Method

A. Kosińska, M. Karamać, R. Amarowicz

Czech J. Food Sci., 2009, 27(10):S119 | DOI: 10.17221/939-CJFS

Protein-polyphenol association may affect polyphenols absorption/bioavailability from gastrointestinal tract and finally modulate their biological activities. Fluorescence spectroscopy has been widely used to investigate the interactions of drugs and proteins. Measuring of quenching of intrinsic fluorescence of proteins can be also applied to study binding affinity of phenolic compounds to proteins. The aim of our study was to investigate interactions between phenolic compounds and proteins (isolated from broad bean seeds) using fluorescence quenching method. Phenolic compounds were extracted from broad bean coats and separated chromatographically...

Characterisation of Polycondensation Products from Amino Acids and Lipid Oxidation Products

A. Adams, V. Kitryte, R. Venskutonis, N. De Kimpe

Czech J. Food Sci., 2009, 27(10):S12 | DOI: 10.17221/631-CJFS

The Maillard reaction, or nonenzymatic browning, includes a complex network of reactions initiated by the condensation reaction of a carbohydrate and an amino compound, and is of utmost importance for the formation of flavour and colour in thermally treated foods. Besides volatile flavour compounds, also brown-coloured polycondensation products, named melanoidins, are produced. In latest years, the interaction of lipid oxidation products in the classical Maillard reaction pathway and vice versa is of particular interest, since it has been shown that the course of both reactions can be modified by the reactants, intermediates and products of...

Study of Resistant Starch (RS) Content in Peas during Maturation

R. Dostálová, J. Horáček, I. Hasalová, R. Trojan

Czech J. Food Sci., 2009, 27(10):S120-S124 | DOI: 10.17221/935-CJFS  

Total starch (TS), amylose and resistant starch (RS) were determined in the sets of smooth pea and wrinkled pea varieties in the years 2006-2008. Starch content of smooth peas varied in the range 53.61-57.23%. Average amylose content was 27.8%. Resistant starch content varied from 2.07% to 6.31%. Content of starch at wrinkled pea varied from 26.57% to 32.55%. Average amylose content was 76.82% of total starch. Content of total starch increases continually during seed development. The dependence of total starch on determined dry mass in harvested sample can be defined by equation γ = 1.2427 × -6.5611, by determination coefficient R²...

Content of Higher Fatty Acids in Green Vegetables

R. Vidrih, S. Filip, J. Hribar

Czech J. Food Sci., 2009, 27(10):S125-S129 | DOI: 10.17221/621-CJFS  

Green vegetables are considered an important source of some nutritionally important constituents that have health benefits (e.g. vitamins, minerals, antioxidants, fibre). Epidemiological data suggest that consuming a diet rich in fruit and vegetables can lower the risks for chronic diseases, such as cardiovascular diseases and cancer. Over the past 100-150 years, there have been enormous increases in the consumption of omega-6 fatty acids due to the increased intake of vegetable oils from various seeds. Studies have indicated that a high intake of omega-6 fatty acids shifts the physiological state to one that is prothrombotic and pro-aggregatory, whereas...

Changes of Sunflower Oil Polyenoic Fatty Acids under High Temperatures

K. CIHELKOVÁ, M. ZÁRUBOVÁ, I. HRÁDKOVÁ, V. FILIP, J. ŠMIDRKAL

Czech J. Food Sci., 2009, 27(10):S13-S16 | DOI: 10.17221/918-CJFS  

Heat induced cis-trans isomerisation of sunflower oils depending on temperature, reaction time and original content of linoleic acid was investigated. The content of isomeric fatty acids was determined by gas chromatography and the content of polymers by gel permeation high-performance liquid chromatography. The content of trans fatty acids increased with time and with temperature and a rate of cis-trans isomerisation and polymerisation depends on the temperature according to Arrhenius equation. The content of polymers was significantly lower in sunflower oil with high content of oleic acid because of the low concentration of linoleic...

Evaluation of Shelf Life and Heat Treatment of Tomato Products

A. Rajchl, H. Čížková, M. Voldřich, M. Jirušková, R. Ševčík

Czech J. Food Sci., 2009, 27(10):S130-S133 | DOI: 10.17221/1096-CJFS  

Model storage experiments of pasteurised tomato puree and ketchup were carried out. The sets of samples were boiled at 100°C, during the heating the changes of selected markers were followed and correlated with the sensory evaluation, the markers were: furosine, 2-furaldehyde, 5-hydroxymethyl-2-furaldehyde (HMF) and colour (expressed as: L, a*, b*, a*/b* and ΔE). The suitability of selected markers for the assessment of temperature impact on tomato products was evaluated. The correlation matrix for the followed markers of the tomato puree and ketchup was calculated and the courses of changes (expressed as velocity constant) of the...

Nutritional Quality of Commercial Fruit Baby Food

H. Čížková, R. Ševčík, A. Rajchl, M. Voldřich

Czech J. Food Sci., 2009, 27(10):S134-S137 | DOI: 10.17221/616-CJFS  

Commercial fruit baby food is a preserved fruit product usually made with fruit purees, sugar, water and variable additives (thickening agents, antioxidants, etc.). As the foodstuffs intended for particular nutritional uses, baby foods for infants and young children conforms to a set of strict guidelines e.g. maximum levels for pesticide residues, microbiological contamination, addition of additives, labelling, etc. However, being an important supplement to children diet and/or for their progressive adaptation to ordinary food, the nutritional quality of commercial fruit baby food in very important. Ten samples of commercial fruit baby food from the...

Improvement of Nutritional Value of Tomatoes under Salt Stress Conditions

Z. Šmídová, R. Izzo

Czech J. Food Sci., 2009, 27(10):S138-S139 | DOI: 10.17221/1103-CJFS  

The aim of the work was to evaluate the change in antioxidant content with maturation stage in tomato berries under elevated salinity conditions. The examined antioxidants were lipoic acid, vitamin C and vitamin E. It was found that in the majority of berries examined the content of dihydrolipoic acid, reduced ascorbate and a-tocopherol increased with maturation. Furthermore, the interplay between them was shown. These results are of great importance also from nutritional and health point of view.

Influence of Cheese Type and Maturation Time on the Early Maillard Reaction in Cheese

U. Schwietzke, U. Schwarzenbolz, T. Henle

Czech J. Food Sci., 2009, 27(10):S140-S142 | DOI: 10.17221/1111-CJFS  

Formation and degradation of Amadori products (APs) originating from the early Maillard reaction during maturation of three different commercial cheeses, namely Cheddar, Emmentaler and Gouda, was investigated. APs were analysed as the corresponding N-(furoylmethyl) amino acids formed after acid hydrolysis. The contents of furosine, which is a hallmark for Amadori products resulting from derivatisation of lysine at the ε-amino group (ε-APs), ranged from 4 to 20 mg/100 g protein, corresponding to 33 to 159 μmol of lysine Amadori product per 100 g protein in the cheese samples at the start of the ripening period. Furosine contents...

Influence of Heat Treatment on the Formation of Amadori Compounds in Carrots

A. Wellner, Ch. Hüttl, T. Henle

Czech J. Food Sci., 2009, 27(10):S143-S145 | DOI: 10.17221/969-CJFS  

The formation of Amadori products (APs) during heat treatment of carrot juice and dehydration of carrots was studied. APs were measured as the corresponding N-furoylmethyl amino acids (FMAAs) after acid hydrolysis using RP-HPLC. Commercial samples of juices contained up to 108 mg furosine/100 g protein, 18 mg FM-Ala/100g protein, 13 mg FM-Val/100 g protein and 32 mg FM-GABA/100 g protein. The concentrations in dehydrated carrots were extensively higher with up to 1553 mg furosine/100 g protein, 1144 mg FM-Ala/100 g protein, 88 mg FM-Val/100 g protein and 908 mg FM-GABA/100 g protein. Heat treatment of fresh carrot juice caused only a marginal...

Amadori Products - Substrates and Inhibitors for Intestinal Brush Border Glycosidases

A. Seidowski, D. Lunow, T. Henle

Czech J. Food Sci., 2009, 27(10):S146-S148 | DOI: 10.17221/615-CJFS  

The effect of oligosaccharide-derived Amadori products on intestinal disaccharidases was investigated to answer the question, whether these products, ingested in relevant amounts with the daily diet, are degraded by carbohydrate-digesting enzymes and in addition interfere with the digestion of other carbohydrates. Using Caco-2 cells, which served as model for the intestinal brush border, the hydrolysis of peptide-bound Amadori products, prepared from Nα-hippuryllysine and maltose or maltotriose, respectively, as well as of the oligosaccharides was studied. The Caco-2 cells hydrolysed the Amadori products to yield N^α-hippuryl-fructosyl-lysine...

Transformation Pathways of Reductones in the Advanced Maillard Reaction

M. Konečný, K. Cejpek, L. Čechovská, J. Velíšek

Czech J. Food Sci., 2009, 27(10):S149-S152 | DOI: 10.17221/1091-CJFS  

The transformation of methylene-active reducing Maillard intermediates 4-hydroxy-5-methyl-2H-furan-3-one (norfuraneol, 1) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) was studied in heated (at 70-95°C up to 2 h) model aqueous binary systems containing various reactive carbonyl Maillard intermediates. Among them, furan-2-carbaldehyde and its derivatives 5-hydroxymethylfuran-2-carbaldehyde and pyrrol-2-carbaldehyde react intensely with the above reductones resulting in significant formation of consecutive reducing products. The active products formation and changes in total electrochemical activity were evaluated by using...

Release of Protein-Bound N-ε -(γ -glutamyl)-Lysine during Simulated Gastrointestinal Digestion

M. Hellwig, J. Löbner, A. Schneider, U. Schwarzenbolz, T. Henle

Czech J. Food Sci., 2009, 27(10):S153-S155 | DOI: 10.17221/962-CJFS  

N-ε -(γ -glutamyl)-lysine is a crosslinking amino acid formed in food mainly during treatment with microbial transglutaminase (mTG). The purpose of this study was to investigate to which amount isopeptides are detectable in a low-molecular weight peptide fraction after simulated gastrointestinal digestion. Casein, which had been enriched with N-ε -(γ-glutamyl)-lysine by mTG to different extents, was subjected to simulated gastrointestinal digestion and the resulting peptide mixture fractionated into a low- and a high molecular weight fraction (below or above 200-500 Da, respectively) using semipreparative gel...

Cysteine Mediated Formation of N-ε -Carboxymethyllysine (CML) on Proteins

U. Schwarzenbolz, T. Henle

Czech J. Food Sci., 2009, 27(10):S156-S159 | DOI: 10.17221/1106-CJFS  

The reaction of glyoxal with nucleophilic amino acids was monitored for β-casein as well as β-lactoglobulin. As predicted from previous experiments with hippuryl amino acids, a measurable decrease of arginine can be found in the thiol-free β-casein, while the lysine content remained almost unchanged. For β-lactoglobulin, the incubation with glyoxal led to a slight decrease in the lysine content, while the arginine residues remained unmodified. Here, in accordance with nucleophilicity, it is suggested, that mainly cystein residues react with glyoxal. In solutions containing β-casein with or without glutathione, the effects were...

Effect of a "Fast Food" Diet on the Urinary Excretion of Maillard Reaction Products

A. Förster, C. Börner, T. Henle

Czech J. Food Sci., 2009, 27(10):S160-S162 | DOI: 10.17221/1101-CJFS  

The impact of a diet consisting mainly of "fast food" on the urinary excretion of glycation compounds compared to a usual diet was studied. 9 volunteers followed a well defined diet, starting with one day of individual diet of choice followed by four days of "fast food" embedded in two day periods of MRP-free diet. 24 h-urine samples were collected and analysed for contents of free Amadori product and pyrraline. Urinary excretion of the glycation compounds decreased by 70% to a basic level as a consequence of the MRP-free diet. The following "fast food diet" lead to an increase in excretion of both lysine derivatives, giving evidence for no significant...

Methylglyoxal in Manuka Honey - Correlation with Antibacterial Properties

J. Atrott, T. Henle

Czech J. Food Sci., 2009, 27(10):S163-S165 | DOI: 10.17221/911-CJFS  

A perfect linear correlation was found for methylglyoxal levels in 61 samples of Manuka honey, ranging from 189 to 835 mg/kg, and the corresponding antibacterial activities of the samples, which were between 12.4% and 30.9% equivalent phenol concentration. This clearly underlines that methylglyoxal is the dominant bioactive compound in Manuka honey and above concentrations of around 150 mg/kg directly responsible for the characteristic antibacterial properties of Manuka honey. Methylglyoxal can be a suitable tool for labelling the unique bioactivity of Manuka honey.

Isolation of Reaction Products Resulting from Heat-Induced Degradation of Inulin

K. Trabs, N. Kasprick, T. Henle

Czech J. Food Sci., 2009, 27(10):S166-S168 | DOI: 10.17221/921-CJFS  

From inulin which had been heated for 30 min at 200°C, four di-D-fructose dianhydrides (DFDAs) were isolated using flash chromatography and final purification by semipreparative HPLC, followed by identification via NMR spectroscopy. The DFDAs α-D-Fruf-1,2':2,3'-β-D-Fruf (DFA III), α-D-Fruf-1,2':2,1'-β-D-Fruf (DFA I), α-D-Fruf-1,2':2,1'-α-D-Fruf (DFA VII) and β-D-Fruf-1,2´:2,1´-β-D-Fruf were identified. The yield of the isolated DFDAs varied depending on the DP of the used inulin. Using the isolated DFDAs as reference compounds, quantification of the disaccharides...

Lipid Oxidation in Dispersive Systems with Monoacylglycerols

V. Spěváčková, I. Hrádková, M. Ebrtová, V. Filip, M. Tesařová

Czech J. Food Sci., 2009, 27(10):S169-S172 | DOI: 10.17221/1059-CJFS  

Model fat blends with a monoacylglycerol emulsifier with different acyl chain (C10, C12, C14, C16, C18, C18:1, C20, C22) were prepared and stored under oxygen atmosphere 8 weeks at temperature 20°C. Influence of monoacylglycerol on oxidation and oxidation stability of the model fat blends was studied. The model fat blends were prepared by mixing of fully hydrogenated structured fats that contained only palmitic and stearic acid (fully hydrogenated zero-erucic rapeseed oil and fully hydrogenated palmstearin) and half-refined soybean oil. Lipid oxidation was measured by determination of the peroxide value. Volatile oxidation products were detected by...

Oxidative Changes of Lipids during Microwave Heating of Minced Fish Flesh in Catering

E. Abd El-Moneim Mahmoud, J. Dostálová, D. Lukešová, M. Doležal

Czech J. Food Sci., 2009, 27(10):S17-S19 | DOI: 10.17221/948-CJFS  

The influence of microwave heating (microwave oven Electrolux, 2450 MHz, 400 W) from 8 up to 24 min on the oxidation and fatty acid composition of lipids of common carp (Cyprinus carpio) and Atlantic mackerel (Scomber scombrus) minced fish flesh were studied. The heating treatment at all conditions reduced moisture and therefore, increased lipid and dry matter contents. The isolated lipids were subjected to the following analyses: peroxide value, acid value and content of conjugated dienes (by absorbance at 232 nm). The free fatty acid content in the lipid fraction of the fish flesh was significantly reduced by cooking. Conjugated diene...

Oxidation of Olive Oils during Microwave and Conventional Heating for Fast Food Preparation

E. Abd El-Moneim Mahmoud, J. Dostálová, J. Pokorný, D. Lukešová, M. Doležal

Czech J. Food Sci., 2009, 27(10):S173-S177 | DOI: 10.17221/963-CJFS  

The oxidation stability of extra virgin and refined olive oils produced in different countries were studied under different conditions of microwave heating (microwave oven Electrolux, 2450 MHz, 500 W) and conventional heating (200°C). Oils were heated in a microwave oven and in a conventional oven for 0, 3, 6, 9, 12, 15, 20, 25, and 30 minutes. The evaluated parameters were peroxide value, content of conjugated dienes, conjugated trienes (determined by absorbance at 233 nm and 274 nm, respectively), and fatty acid composition by GC. During microwave and conventional heating peroxide values and contents of dienoic compounds differed significantly between...

Oxidation Changes of Vegetable Oils during Microwave Heating

D. Lukešová, J. Dostálová, E. El-Moneim Mahmoud, M. Svárovská

Czech J. Food Sci., 2009, 27(10):S178-S181 | DOI: 10.17221/929-CJFS  

Oxidation changes of different types of vegetable oils were studied during microwave heating. Samples of vegetable oils (rapeseed, sunflower, soybean and corn oil), commercially available at the market in the Czech Republic, were heated in a microwave oven. Parameters as peroxide value, conjugated dienes and trienes levels were determined in oil samples before and after heating in the period from 3 to 30 minutes.

Lipid Oxidation Inhibition in Frozen Farmed Salmon (Oncorhynchus kisutc h ): Effect of Packaging

A. Rodríguez, M. Trigo, R. Pérez, J. M. Cruz, P. Paseiro, S. P. Aubourg

Czech J. Food Sci., 2009, 27(10):S182-S184 | DOI: 10.17221/1084-CJFS  

: Coho salmon (Oncorhynchus kisutch) has recently attracted a great interest as a farmed product. This research focuses on its commercialisation as a frozen product. For it, an advanced storage technology combining vacuum and a polyphenolic rich-film was applied for a 9-months storage period (-18°C). The study was addressed to lipid hydrolysis and oxidation changes and to endogenous antioxidant content in salmon muscle. No effect of packaging conditions could be observed on free fatty acid formation. However, vacuum packaging conditions provided a partial inhibition of primary (peroxide) and secondary (anisidine value) lipid oxidation development;...

Heating of Plant Oils-Fatty Acid Reactions versus Tocopherols Degradation

Z. Réblová, D. Tichovská, M. Doležal

Czech J. Food Sci., 2009, 27(10):S185-S187 | DOI: 10.17221/968-CJFS  

Relationship between polymerised triacylglycerols formation and tocopherols degradation was studied during heating of four commercially accessible vegetable oils (rapeseed oil, classical sunflower oil, soybean oil and olive oil) on the heating plate with temperature 180°C. The content of polymerised triacylglycerols 6% (i.e. half of maximum acceptable content) was achieved after 5.3, 4.2, 4.1, and 2.6 hours of heating for olive oil, soybean oil, rapeseed oil and sunflower oil, respectively, while decrease in content of total tocopherols to 50% of the original content was achieved after 3.4, 1.6, 1.3, and 0.5 hours of heating for soybean oil, rapeseed...

Variability of Lutein Content in Peas (Pisum sativum L.) in Relation to the Variety, Season and Chlorophyll Content

M. Holasová, R. Dostálová, V. Fiedlerová, J. Horáček

Czech J. Food Sci., 2009, 27(10):S188-S191 | DOI: 10.17221/1075-CJFS  

Lutein and β-carotene contents in 32 samples of field peas with green (

Changes of Vitamin C Content in Relation to the Range of Accumulation of Cd, Pb and Zn in Potato Tubers

J. Musilová, J. Bystrická, J. Tomáš, Z. Poláková, S. Melicháčová

Czech J. Food Sci., 2009, 27(10):S192-S194 | DOI: 10.17221/614-CJFS  

The changes of vitamin C content in relation to Cd, Pb and Zn accumulation in 6 potatoes varieties: very early (Junior, Impala), early (Livera), middle early (Agria), medium-late (Asterix, Desirée) were surveyed in this work. The soil used in pot trial had pseudototal (in soil extract of aqua regia

Mechanism and Polyphenols Involved in the Browning Reaction of Olives

P. García-García, K. Segovia-Bravo, A. López-López, M. Jaren-Galán, A. Garrido-Fernández

Czech J. Food Sci., 2009, 27(10):S195-S196 | DOI: 10.17221/1099-CJFS  

The purpose of this work was to disclose the mechanisms of the browning reaction produced on the surface of the fresh Manzanilla olive cultivar due to the bruises caused during hand or mechanical harvesting. The role played by the different phenols in the browning reaction and the implication of the enzymes present in the olive flesh have also been studied. The reaction was reproduced in model solutions where olive phenol extracts were put into contact with crude enzymatic olive extracts (active or denaturised) in a solution buffered at the same pH of the olive flesh (5.0) added or not with ascorbic acid to prevent oxidation. The proposed mechanism...

Involvement of Hydrogen Peroxide Formation on Apoptosis Induction by Olive Oil Phenolic Compounds

R. Fabiani, P. Rosignoli, R. Fuccelli, F. Pieravanti, A. De Bartolomeo, G. Morozzi

Czech J. Food Sci., 2009, 27(10):S197-S199 | DOI: 10.17221/913-CJFS  

In the present investigation the ability of different phenolic compounds, either present or not in olive oil, to induce both apoptosis on tumour cells and H₂O₂ accumulation in cell culture medium was assesed. Among the phenols studied we found that tyrosol (p-HPEA), homovanillic alcohol and protocatechuic, o-coumaric, vanillic, homovanillic, ferulic and syringic acids did not induce either apoptosis on HL60 cells or H₂O₂ accumulation, while hydroxytyrosol (3,4-DHPEA), 3,4-dihydroxyphenylacetic acid (3,4-DHPA), 3,4-dihydroxy-hydrocinnamic acid (3,4-DHHC) and gallic acid induced both apoptosis...

Chemical Changes in Chilled Farmed Salmon (Oncorhynchus kisutch): Effect of Previous High Pressure Treatment

A. Rodríguez, I. Ortea, M. Trigo, Y. Sierra, J. M. Gallardo, G. Tabilo-Munizaga, M. Pérez-Won, S. P. Aubourg

Czech J. Food Sci., 2009, 27(10):S20-S22 | DOI: 10.17221/630-CJFS  

Coho salmon (Oncorhynchus kisutch) has recently attracted a great interest as a farmed product. This research focuses on its commercialisation as a chilled product. Thus, the effect of a previous hydrostatic high pressure (HHP) treatment on chemical changes related to quality loss was studied. A marked effect of HHP treatment was observed on lipid hydrolysis (free fatty acid formation), lipid oxidation (primary, secondary and tertiary compounds) and protein breakdown (sarcoplasmic fraction) throughout the chilling storage; however, no influence could be observed on nucleotide degradation and polyene index. Sensory analysis (putrid and amine...

Determination of the Influence of Variety and Level of Maturity on the Content and Development of Carotenoids in Tomatoes

Z. Kotíková, A. Hejtmánková, J. Lachman

Czech J. Food Sci., 2009, 27(10):S200-S203 | DOI: 10.17221/1093-CJFS  

The influence of variety and the level of maturity on the content and composition of carotenoids in tomatoes were monitored in a field experiment in the year 2007. A total of 11 varieties were submitted to this experiment - Albertovské žluté, Bejbino F1, Cristina F1, Bonset F1, Dominato F1, Monika F1, Orkado F1, Start S F1, Stupické polní rané, Tornádo F1 and Rougella F1. A significant difference in the ability of tomatoes to synthesise carotenoids in relation to variety was found. At the mature phase of fruits an average content of carotenoids was determined as 665 μg/g dry mass. The varieties with high content of carotenoids were Bonset F1, Start...

Anthocyanins Content in Blueberries (Vaccinium corymbosumL.) in Relation to Freesing Duration

A. Vollmannová, T. Tóth, D. Urminská, Z. Poláková, M. Timoracká, E. Margitanová

Czech J. Food Sci., 2009, 27(10):S204-S206 | DOI: 10.17221/1069-CJFS  

The changes of total anthocyanins (TA) content in fruit of blueberries in relation to freezing duration are the aim of this study. The samples of 21 chosen cultivars obtained from the research breed station were stored in polyethylene bags in freezing box at temperature -18°C. In ethanolic blueberry extracts TA contents were by spectrophotometric method during the time of 6 months at period of 3 months determined. Significant differences of TA content among the observed cultivars were confirmed. The value interval was 615.8-3206.3 mg/kg. The average TA content in 10 very early, resp. early cultivars was 1655.8 mg/kg, in 5 medium early cultivars 1515.6...

Advances in Chemistry of Isothiocyanate-derived Colourants

K. Cejpek, J. Velíšek

Czech J. Food Sci., 2009, 27(10):S207-S210 | DOI: 10.17221/1092-CJFS  

This study is focused on the reactions of isothiocyanates (ITCs) in the presence of amino compounds leading to coloured structures via substituted 2-thiohydantoins. A series of complementary experiments has been done and appropriate reaction conditions and structural prerequisites have been defined. Low-molecular colourants isolated and characterised from the model systems can be sorted into three groups. Yellow to red diastereomeric dehydrodimers of 2-thiohydantoin derivatives that contain an acidic methylene group are formed in mixtures consisted of ITCs and amino acids with α-methylene group in mild acidic to mild alkaline systems....

Influence of Environmental Factors on Green Asparagus Flavonoids

J. Fuentes, S. Jaramillo, R. Guillén, A. Jiménez, R. Rodríguez, A. Lama, J. Fdez-Bolanos, R. Rodríguez

Czech J. Food Sci., 2009, 27(10):S211 | DOI: 10.17221/613-CJFS

We have previously reported that there is high correlation between antioxidant capacity and total phenol content in green asparagus (RODRÍGUEZ et al. 2005), which suggests that phenols could be mainly responsible for that activity as happens for other plant-derived products (VINSON et al. 1998; KAMAT et al. 2000; NINDO et al. 2003; PELLEGRINI et al. 2003). It has also been established that flavonoids are the most abundant phenolics in green asparagus and that their profile is significantly different among genotypes (FUENTES-ALVENTOSA et al. 2007, 2008). The composition of flavonoids in plants is influenced...

Saponin Profile of Green Asparagus Genotypes

S. Jaramillo, J. Fuentes, R. Rodríguez, A. Jiménez, G. Rodríguez, A. Lama, J. Fdez-Bolanos, R. Guillén

Czech J. Food Sci., 2009, 27(10):S212 | DOI: 10.17221/957-CJFS

Among the phytochemicals found in green asparagus, phenolics and saponins represent the major groups of bioactive compounds. The first are mainly related to the antioxidant activity of this product; and the distinct saponins detected in green (triguero) asparagus influence both its organoleptic and bioactive properties. The main objective of the present work is the characterisation of the saponins profile from distinct genotypes of the green asparagus. Their analysis by HPLC-MS (High Performance Liquid Chromatography-Mass Spectrometry) have revealed that the content and composition of saponins from green asparagus are significantly different from those...

Determination of Caffeine Content in Tea and Maté Tea by using Different Methods

D. Komes, D. Horžić, A. Belščak, K. Kovačević Ganič, A. Baljak

Czech J. Food Sci., 2009, 27(10):S213-S216 | DOI: 10.17221/612-CJFS  

Caffeine-containing products have been consumed for hundreds of years for their pleasant flavor and stimulating effects. In recent years, caffeine received increasing attention in food and pharmaceutical industries, due to its pharmacological properties which comprise stimulation of the central nervous system, peripheral vasoconstriction, relaxation of the smooth muscle and myocardial stimulation. The aim of this study was to determine the content of caffeine in five types of tea (white, yellow, green, oolong, black) and two types of maté tea (green maté and roasted maté tea). The content of caffeine was determined by using four different methods:...

Determination of Sterols in Dairy Products and Vegetable Fats by HPLC and GC Methods

I. Borkovcová, E. Janoušková, M. Dračková, B. Janštová, L. Vorlová

Czech J. Food Sci., 2009, 27(10):S217-S219 | DOI: 10.17221/1073-CJFS  

Cholesterol concentrations in goat milk, goat milk cheeses, ewe's milk, ewes milk cheeses, dairy bioproducts, and concentrations of cholesterol, stigmasterol and sitosterol in butter, butter with added vegetable fats and margarines were evaluated by RP HPLC method. Parallel analyses by capillary GC were performed. Prior to the final chromatographic analyses the saponification step was used, followed by the extraction of the unsaponificable residue into n-hexane. Parameters of RP HPLC method were compared with parameters of GC determination. The detection limits (LOD) determinated on the bases of blank samples analysis were 5.2 mg/kg for cholesterol,...

Sterols, Sterol Oxides and CLA in Typical Meat Products from Pigs Fed with Different Diets

C. Annaratone, A. Caligiani, M. Cirlini, L. Toffanin, G. Palla

Czech J. Food Sci., 2009, 27(10):S220-S223 | DOI: 10.17221/611-CJFS  

The effect on sterol stability and CLA content in meats from pigs fed with diets having different contents of oleic and linoleic acid was studied, considering typical Italian products seasoned with or without nitrates and ascorbates. Results showed that the increase of oleic acid in the diet leads to seasoned products with higher contents of oleic acid and lower content of linoleic acid and CLA. A different partition of sterols and sterol oxides was observed in the fat and in the muscle of all the products, with slightly higher amounts of cholesterol and sterol oxides in the muscle. Meat products seasoned in presence of ascorbates showed slightly lower...

Hydroperoxide Formation of Steryl Ester

M. Lehtonen, S. Kemmo, A.-M .Lampi, V. Piironen

Czech J. Food Sci., 2009, 27(10):S224 | DOI: 10.17221/936-CJFS

Phytosterols and -stanols are added to food products because of their known ability to lower serum cholesterol levels. They are applied either in their free or esterified forms, i.e. as fatty acid esters. Sterols are known to form variety of oxidation products under exposure to heat, light and metal contaminants, for example in food processing conditions. Since these oxides may have adverse health effects, the oxidation process needs to be studied. Until recently, sterol oxidation studies have concentrated on following the formation of secondary oxidation products in free sterol and steryl esters, but little is known about the oxidation of steryl esters...

Changes in Sterols, Fatty Alcohol and Triterpenic Alcohol during Ripe Olive Processing

A. López-López, F. Rodríguez Gómez, A. Cortés-Delgado, A. Garrido-Fernández

Czech J. Food Sci., 2009, 27(10):S225-S226 | DOI: 10.17221/1109-CJFS  

The unsaponifiable matter, sterols and fatty and triterpenic alcohol changes during ripe olive processing were studied. At the end of processing, the values of most of these parameters were within the limits established by the EU Directives for the classification of olive and pomace oils into their diverse categories; but the evaluations were contradictory and showed that such Directives may not be appropriate for expressing their real quality. The univariate analysis of variance showed significant effects of cultivars or processing steps (ps) on unsaponifiable matter, β-sitosterol, delta5-avenasterol, total sterols, 1-docosanol, 1-tetracosanol...

HS-SPME/GCxGC/TOF-MS: A Powerful Tool for Off-flavors Identification in Italian Muscat-based Wines

M. BORDIGA, J. D. COISSON, F. TRAVAGLIA, G. PIANA, M. ARLORIO

Czech J. Food Sci., 2009, 27(10):S227 | DOI: 10.17221/906-CJFS  

Muscat Blanc a Petits Grains grape (Vitis vinifera L.) is used for the production of Asti (or Asti Spumante) and Moscato d'Asti wines from Piedmont (Italian DOCG designation, D.M. 29-11-1993). The sweet floral aroma from Muscat grapes is a required sensorial quality of these wines. The evolution of the volatile aroma in wine is correlated to many parameters (grape variety, winemaking practices, microbial starters and microflora development, ageing). The oxidation of some compounds was reported to be of fundamental importance in Muscat-type wines aroma (ARLORIO et al. 2005). The unexpected development of off-flavors is a common accident,...

l-Malic Acid Effect on Organic Acid Profiles and Fermentation By-products in Apple Wines

A. Kunicka-Styczyńska, E. Pogorzelski

Czech J. Food Sci., 2009, 27(10):S228-S231 | DOI: 10.17221/1063-CJFS  

Industrial wine yeasts Saccharomyces bayanus and two interspecies hybrids (S. cerevisiae × S. bayanus) were checked for their suitability for fermentation of apple musts with different L-malic acid content (4, 7 and 11 g/l). The fermentation profiles including main organic acids, acetaldehyde, diacetyl, glycerol, esters and polyphenols were presented. The results were obtained by HPLC method (organic acids, acetaldehyde, glycerol, diacetyl), GC (esters), colorimetrically (polyphenols) and enzymatically (L-malic acid, ethanol). Although the fermentation profiles of wines were characteristic for specific yeast strains, similarities in organic acid profiles...

Mathematical Modelling of Some Nutrient Losses during Heat Treatment of Stewed Apples

F. Courtois, L. Vedrenne, S. Georgé

Czech J. Food Sci., 2009, 27(10):S23-S26 | DOI: 10.17221/966-CJFS  

Vitamin C (later noted VITC) and polyphenols (later noted PP) were regarded as main nutritional markers in the transformation process of stewed apples after an in situ measurement campaign at two leading French industrials on that matter. Experiments on pilots with the CTCPA of Avignon made it possible to create a small experimental data base whose treatment is the core of this article. The objective of this work is to check if the experimental data collected at the CTCPA facility can be represented by a single model of 2 separate first order reactions, with or without Arrhenius, under varying processing temperatures.

Distribution of S-alk(en)yl-l-cysteine Sulfoxides in Garlic (Allium sativum L.)

J. Horníčková, J. Velíšek, J. Ovesná, H. Stavělíková

Czech J. Food Sci., 2009, 27(10):S232-S235 | DOI: 10.17221/610-CJFS  

This study was devoted to distribution of S-alk(en)yl-L-cysteine sulfoxides (particularly alliin, methiin, and isoalliin) in plants of Allium sativum L. and to diversity of selected groups of garlic clones representing the three basic garlic morfotypes (i.e. flowering plants, scape absent and semi-bolters - this classification is based on IPGRI descriptors). The content of S-alk(en)yl-L-cysteine sulfoxides, important non-volatile precursors flavour-active compounds, was determined in four parts (roots, bulbs, false stems, and leaves) of six different clones of garlic (Allium sativum L.) plants collected during the whole...

Rutin Content in Buckwheat Enriched Bread and Influence of its Consumption on Plasma Total Antioxidant Status

T. Bojňanská, H. Frančáková, P. Chlebo, A. Vollmannová

Czech J. Food Sci., 2009, 27(10):S236-S240 | DOI: 10.17221/967-CJFS  

The goal of this study is the evaluation of enriched bread prepared with an addition of buckwheat as a source of biologically active components in nutrition. Experimental pastry was baked using buckwheat wholegrain flour blended with wheat flour in different portions (10%, 20%, 30%, 40% and 50%) in order to observe the influence of buckwheat addition on dough processing and the quality of the final baked products. Taking into account the overall acceptability rating, it was concluded that bread with an addition of up to 30% of buckwheat could be baked with satisfactory evaluation results. The content of rutin in loaves in a consumable form prepared...

Effects of Infrared Radiation on Protein Solubility and Antioxidants Content in Maize Flour

S. Zilic, V. Hadzitaskovis-Sukalovic, M. Milasinovic, D. Tvrzic, M. Maksimovic

Czech J. Food Sci., 2009, 27(10):S241 | DOI: 10.17221/1077-CJFS

The objective of these studies was to observe the effects of the process of micronisation on the protein solubility, as well as, on contents of antioxidants and vitamins in whole maize flour. Maize hybrids differing in the kernel colour developed at the Maize Research Institute, Zemun Polje, Belgrade, Serbia, were selected for these studies. The semi-flint hybrid ZP 633 has pronounced yellow kernels; the pericarp of ZP Rumenka is dark red, while the hybrid ZP 551b is characterised by a white colour of kernels. Grain of selected genotypes was used in the production of flour. Whole flours were produced by milling of intact maize fresh grain in a stone...

Barley Grain as a Source of Health-Beneficial Substances

N. Březinová Belcredi, J. Ehrenbergerová, S. Běláková, K. Vaculová

Czech J. Food Sci., 2009, 27(10):S242-S244 | DOI: 10.17221/609-CJFS  

Barley is an excellent source of non-starch polysaccharides, i.e. soluble fiber (β-glucans and arabinoxylans), it contains many important vitamins (vitamin E and vitamin B-complex) and enzymes (superoxide dismutase, catalase). A set of the malting varieties and a line KM 1057 had statistically significantly higher content of arabinoxylans (4.40-5.58%) compared to the other KM lines (CZ origin) and the variety Merlin (Canada origin) (3.51-3.64%). Content of β-glucans in grain of varieties/lines was in a reverse order. The variety Merlin and lines KM (4.10-6.08%) had higher β-glucan content compared to the malting varieties and lines KM...

Antioxidant Activities and Total Phenolics of Acacia Honey

M. Krpan, K. Marković, G. Šarić, B. Skoko, M. Hruškar, N. Vahčić

Czech J. Food Sci., 2009, 27(10):S245-S247 | DOI: 10.17221/1112-CJFS  

The antioxidant activities and total phenolic content of 30 samples of acacia honey from Croatian territory were analysed. Phenolics were determined by the modified Folin-Ciocalteu method, antiradical activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and potential antioxidant activity using the ferric reducing antioxidant power (FRAP) method. In all samples, physicochemical parameters (water content, electrical conductivity, total reducing sugars, sucrose content, acidity, hydroxymethylfurfural content, prolin content, optical rotation, diastase activity and invertase activity) were measured according to Croatian legislation and International...

Content of Bioactive Components in Chosen Cultivars of Cranberries (Vaccinium vitis-idaea L.)

A. Vollmannová, J. Tomáš, D. Urminská, Z. Poláková, S. Melicháčová, L. Krížová

Czech J. Food Sci., 2009, 27(10):S248-S251 | DOI: 10.17221/940-CJFS  

The of relation between chosen macro- and microelements, total polyphenol (TP) and anthocyanin content (TA) and antioxidant capacity (TAC) in 6 selected cultivars of cranberries (Sussi, Linnea, Sanna, Runo Bielawski, Ida, Koralle) is the aim of this study. The influence of cultivars on macro- and microelements content was confirmed. The Mg content was in interval 478.3-555.2 mg/kg, K 5690-7690 mg/kg, Fe 10.7-29.3 mg/kg, Cr 0.5-0.8 mg/kg, Cu 3.5-5.0 mg/kg and Zn 8.1-9.8 mg/kg. The lowest Mg, Cr, and Cu contents were determined in cultivar Ida with the highest TP and TA contents. TA contents in observed cultivars were in interval 221.778-498.503 mg/kg,...

Lignans in Flaxseed

A. Krajčová, V. Schulzová, J. Hajšlová, M. Bjelková

Czech J. Food Sci., 2009, 27(10):S252-S255 | DOI: 10.17221/1062-CJFS  

Lignans are phytoestrogens which are present in a wide variety of plants. Epidemiological studies indicate that phytoestrogen-rich diets reduce risk of various hormone-dependent cancers, heart disease, and osteroporosis. One of the reachest dietary sources of lignans are flaxseeds, with glycosides of secoisolariciresinol (SECO) and matairesinol (MAT) as the major components. In this study LC-MS/MS method for the determination of plant lignans SECO and MAT in flaxseed was developed for analysis of a wide range of samples: (I) nine cultivars of oil flax treated with two types of fertilisers containing humic acids and (ii) fibre flax cultivar...

Anticancer Activity of Lignan from the Aerial Parts of Saussurea salicifolia (L.) DC.

G. Chunsriimyatav, I. Hoza, P. Valášek, S. Skrovanková, D. Banzragch, N. Tsevegsuren

Czech J. Food Sci., 2009, 27(10):S256-S258 | DOI: 10.17221/1097-CJFS  

Aerial parts of Saussurea salicifolia (L.) DC were studied for their lignan and flavonoids in solvent chloroform and n-butanol of ethanolic extract. Isolation and identification of phenolic compounds of the chloroform and n-butanol fractions were performed with Dionex HPLC-DAD system with water-methanol gradients in 4 different wave lengths (235 nm, 254 nm, 280 nm and 340 nm), using online UV and LC-MS as described previously. 9-OH-pinoresinol which is a lignan with anticancer activity was dominated in the chloroform fraction, whereas mainly flavonoid glycosides like quercetin-3-O-galactoside, apigenin-7-O-rhamnoside with...

Determination of Phenolic Compounds in Saussurea salicifolia (L.) DC. by HPLC

G. Chunsriimyatav, 2^*, I. Hoza, P. Valášek, S. Skrovanková, D. Banzragch, N. Tsevegsuren

Czech J. Food Sci., 2009, 27(10):S259-S261 | DOI: 10.17221/947-CJFS  

The flavonoid aglycone content of ethyl acetate fraction of Saussurea salicifolia (L.) DC was analysed by the HPLC "Agilent" 1100 with Alltech C18 μm column, UV254 detector, flow rate: 1 ml/min, mobile phase: acetonitrile: water:acetic acid (36:65:1). Eleven flavonoid aglycones in the ethyl acetate fraction of Saussurea salicifolia were detected by HPLC analysis. The quantification of each compound was done according to the peak area measurements which were reported in calibration curves of the corresponding standards. The result revealed that Saussurea salicifolia consists of flavonoid aglycones of quercetin (28.62%) and kaempferol...

Changes in Ewe's Milk Composition in Organic versus Conventional Dairy Farms

I. Revilla, M. A. Lurueña-Martínez, M. A. Blanco-Lopez, J. Viñuela-Serrano, A. M. Vivar-Quintana, C. Palacios

Czech J. Food Sci., 2009, 27(10):S263-S266 | DOI: 10.17221/941-CJFS  

The aim of this work was to determine the effect of organic production system on ewe's milk quality. Bulk tank ewe's milk from flocks of two production systems (organic and conventional) all of them from the same geographical area (Zamora, Spain) were used to investigate changes in physico-chemical properties including the composition in fatty acids. The metal contents (Fe, Cu, Zn, Mn, Se, Mo, Ba, As, Hg, Pb) and the presence of antibiotics and pesticides in the meat were also studied. The type of production system was seen to elicit a significant effect on pH, total acidity and on the fatty acid composition. Organic milk showed significantly higher...

Comparison of the Sensory Characteristics of Suckling Lamb Meat: Organic vs Conventional Production

I. Revilla, M. A. Lurueña-Martínez, M. A. Blanco-Lopez, A. M. Vivar-Quintana, C. Palacios, P. Severiano-Pérez

Czech J. Food Sci., 2009, 27(10):S267-S270 | DOI: 10.17221/949-CJFS  

40 L. dorsi muscles from the left half carcass of suckling lambs raised under both organic and conventional systems were evaluated by a sixteen-member trained panel, following QDA methodology. After developing a common vocabulary for the evaluation of characteristics, 30 meat descriptors in raw and grilled meat were selected. Additionally, overall appreciation was evaluated by 140 consumers in a home-use test. The results obtained show that the appearance of the organic meat was more fibrous, darker, and with a lower aroma intensity than the conventional counterpart, but with no differences in homogeneity or juiciness. In grilled meat, the organic...

Modelling the Effect of Headspace Oxygen Level on the Degradation of Vitamin C in a Model Fruit Juice

I. Van Bree, S. Samapundo, F. Devlieghere, B. De Meulenaer

Czech J. Food Sci., 2009, 27(10):S27 | DOI: 10.17221/1110-CJFS

Fruit juices are a significant source of vitamin C in the human diet and therefore their nutritional value is mainly related to the amount vitamin C they contain (KABASAKALIS et al. 2000; MANSO et al. 2001; SHINODA et al2005; BERLINET et al2006). However, vitamin C (which also commonly known as ascorbic acid) is readily oxidised and degraded at different rates depending on storage conditions like temperature, the presence of oxygen or trace metals, light exposure etc. (KABASAKALIS et al. 2000). In the presence of oxygen, ascorbic acid (AA) is oxidised to dehydroascorbic acid (DHA), which is itself then further hydrolysed...

Main Chemical Changes in Proteins and Structure of Egg Treated with High Pressure Homogenisation

R. Marco-Molés, I. Hernando, E. Llorca, I. Pérez-Munuera

Czech J. Food Sci., 2009, 27(10):S271-S273 | DOI: 10.17221/1108-CJFS  

The aim of this work was to study the main chemical changes in the protein fraction (SDS-PAGE) and the microstructure (TEM) of whole liquid egg treated with HPH and stored one week at 4°C. In the electrophoretic study, no changes were observed after the treatments neither after one week of refrigerated storage in the water-soluble proteins of the samples, indicating that no proteolysis was produced. The typical structure of the egg lipoprotein matrix was maintained after the HPH treatments and one week of refrigerated storage. However, a progressive disaggregation of the protein granules was observed, especially when high intensity HPH treatment was...

Comparative Lipid Composition Study in Farmed and Wild Blackspot Seabream (Pagellus bogaraveo)

V. Álvarez, M. Trigo, S. Lois, D. Fernández, I. Medina, S. P. Aubourg

Czech J. Food Sci., 2009, 27(10):S274-S276 | DOI: 10.17221/920-CJFS  

During the latest decades, the fish trade has accorded an increasing attention to aquaculture development as a source of marine food products. In this sense, blackspot seabream (Pagellus bogaraveo) has recently attracted a great commercial interest as a farmed product. This work provides a comparative lipid composition study between wild and farmed individuals. For it, three different edible zones (ventral, dorsal and tail white muscles) were considered. From a nutritional point of view, lipid composition of farmed and wild blackspot seabream showed valuable lipid parameters (total polyunsaturated fatty acids, total ω3/total ω6 fatty...

Chemical Changes in Chilled Farmed Sea Bass (Dicentrarchus labrax): Effect of Advanced Icing Conditions

J. Pena, M. Trigo, G. Bouzada, D. Fernández, J. Barros-Velázquez, S. P. Aubourg

Czech J. Food Sci., 2009, 27(10):S277-S279 | DOI: 10.17221/1080-CJFS  

The present research was focused on the commercialisation of fresh farmed sea bass (Dicentrarchus labrax). A slurry ice prototype (60% water/40% ice) coupled to an ozone generator (700 mV, 0.17 mg/l) was tested for the slaughtering and chilling storage (up to 7 days) of this species; comparison with slurry ice treatment alone was undergone. The study was addressed to chemical constituent changes (autolysis, lipid hydrolysis and oxidation, volatile amine formation) in fish muscle related to quality loss; comparison to sensory assessment (skin, eyes, external odour, gills, consistency) was carried out. Increasing values (P < 0.05) with...

Oxygen Transfer coupled to Oxidation Reactions: Numerical Tool for Optimizing Nutritional Quality of Food

C. Pénicaud, V. Guillard, S. Peyron, N. Gontard

Czech J. Food Sci., 2009, 27(10):S28 | DOI: 10.17221/952-CJFS

Dissolved oxygen, due to atmospheric oxygen transfer through food, lowers the overall nutritional, chemical, and physical qualities of food during storage and marketing, causing food product less acceptable or unacceptable to consumers. Oxygen can react with all food components: lipids, proteins, sugars, and vitamins. To imagine new strategies of protection of food, it is necessary to evaluate oxygen transfer and to couple this transfer to chemical reactions. In this work, ascorbic acid oxidation under aerobic conditions has been studied. The objective is to model ascorbic acid degradation regarding both ascorbic acid and oxygen influence, the last...

Detection of Foreign Enzyme Addition into the Adulterated Honey

M. Voldřich, A. Rajchl, H. Čížková, P. Cuhra

Czech J. Food Sci., 2009, 27(10):S280-S282 | DOI: 10.17221/1066-CJFS  

Natural honey contains several enzymes, which are produced by bees (salivary secretion) and some are found in the nectar or pollen. The most important enzymes are amylases, invertases, glusidases, catalases, fosfatases and other. The activity of diastase (α-, β-, γ-amylase) is the important quality parameter of honey, according to the Directive 2001/110/CE the diastase activity (diastase number) must not be less than or equal to 8, for some kinds of honey also higher or equal to 3 (in these cases the HMF must not be higher than 15 mg/kg). Diastase is used as a marker to evaluate the freshness or the heat damage of honey. When honey...

The Improvement of Sensory Quality and Texture Properties of Gluten Free Bread Fortified with Ca

U. Krupa-Kozak, M. Wronkowska, M. Soral-Śmietana, A. Troszyńska, J. Sadowska

Czech J. Food Sci., 2009, 27(10):S283 | DOI: 10.17221/608-CJFS

Celiac disease is a gluten-sensitive entheropathy. Later studies suggest an increasing prevalence of that disease, likely due to the development of more sensitive methods of screening. Cereals containing prolamins such as wheat, rye, barley, and oat are toxic for celiac patients, whereas corn, rice, sorghum and buckwheat are considered to be safe. The reaction to gluten ingestion by patients suffering from that chronic disease is inflammation of the small intestine leading to the malabsorption of several important nutrients, vitamins and minerals, especially of calcium and iron. Osteopenia and osteoporosis are a frequent complication accompanying coeliac...

Influence of the Addition of Buckwheat Flour on Gluten Free Bread Quality and Antioxidant Capacity

M. Wronkowska, D. Szawara-Nowak, D. Zielińska, A. Troszyńska, M. Soral-Śmietana

Czech J. Food Sci., 2009, 27(10):S284 | DOI: 10.17221/607-CJFS

The diet based on gluten free products is characterised by a low content of some nutritional components such as proteins and mineral components, as well as non-nutritional but physiologically important components like dietary fibre. Buckwheat grains are a rich source of proteins, which have a high biological value due to the well-balanced amino-acids composition, although its digestibility is relatively low. The aim of the present research was to investigate the influence of buckwheat flour addition on gluten free bread quality and their antioxidant capacity. In this study, own gluten free bread formula, composed of corn starch, potato starch, salt,...

Quality Properties of White Bread with Native and Extruded Wheat Bran Supplements

Ž. Ugarčić-Hardi, D. Koceva Komlenić, M. Jukić, A. Kuleš, I. Jurkin

Czech J. Food Sci., 2009, 27(10):S285 | DOI: 10.17221/946-CJFS

The addition of wheat bran increases the nutritional value of bread, but at the same time, decreases the dough rheological properties and taste of bread. Many investigations showed that extruded bran has less negative effects on bread texture and mouth feel in comparison with native wheat bran. Besides, new articles can be found on the cholesterol-lowering effects of extruded wheat bran. Therefore, the goal of this study was to compare the quality parameters of bread fortified with native and extruded bran. Wheat flour T-550 was used with the supplement of 7, 14, 21 and 28% fine milled native and extruded bran. Samples with 28% of native and extruded...

On the Generation of Bioactive Trigonelline Degradation Products upon Coffee Roasting and their Bioappearance after Coffee Consumption

R. Lang, T. Hofmann

Czech J. Food Sci., 2009, 27(10):S29 | DOI: 10.17221/629-CJFS

Besides caffeine, the betaine N-methyl nicotinic acid, also known as trigonelline, is commonly reported as the second most abundant alkaloid in raw coffee beans. Upon roasting of coffee beans, trigonelline is partially decomposed to give volatile pyridines as well as non-volatile compounds such as N-methylpyridinium ions, nicotinic acid, and methyl nicotinate. As N-methylpyridinium ions were recently found to exhibit phase I/II biotransformation enzyme modulating activity in vitro as well as in vivo (SOMOZA et al. 2003), and nicotinic acid, methyl nicotinate, together with nicotinamide, exhibit vitamin B3 activity...

Chemical and Structural Changes in White Sauces Thawed by Microwave or Conventional Oven

L. M. Guardeño, E. Llorca, I. Pérez-Munuera, A. Quiles, I. Hernando

Czech J. Food Sci., 2009, 27(10):S290-S292 | DOI: 10.17221/943-CJFS  

Proteins, lipids and structural changes in white sauces after being stored at -18°C and thawed by microwave and conventional oven were studied in this work. The total crude and soluble protein fractions were quantified by N-Kjeldahl. The acidity grade and oxidation spectrophotometric parameters (k₂₃₂ and k ₂₇₀) were used to analyse the lipid fraction. In addition, confocal scanning laser microscopy (CSLM) was used to study the structure of the sauce. The results showed that the total crude protein fraction increased in the thawed samples if compared to the freshly-prepared samples, mainly when microwave oven was used. However,...

The Influence of Interesterification of Structured Fats on the Properties of the Fat Blends

M. Tesařová, M. Zárubová, V. Filip, V. Spěváčková, J. Šmidrkal

Czech J. Food Sci., 2009, 27(10):S293-S296 | DOI: 10.17221/1088-CJFS  

Consistency, rheology and melting/solidification characteristics of model fat blends (FB) on the basis of interesterified structured fats (SF) are discussed. SF were prepared by an alkaline catalysed random interesterification of fully hydrogenated coconut (FHCO) and high-erucic rapeseed (FHHERO) oils with variable molar ratio (2:1; 1.4:1; 1:1; 1:1.4 and 1:2) of the medium chain (M; C8:0-C14:0) and long chain (L; C16:0-C22:0) saturated fatty acids (FA) to find out, if stearic/arachic/behenic acids can substitute palmitic/stearic acids in SF. This substitution in SF is possible at molar ratios M:L 2:1 and 1.4:1 from the point of view of melting and...

The Effect of Ultrasound Pre-Treatment and Air-Drying on the Quality of Dried Apples

M. Opalić, Z. Domitran, D. Komes, A. Belščak, D.. Horžić, D. Karlović

Czech J. Food Sci., 2009, 27(10):S297-S300 | DOI: 10.17221/606-CJFS  

In order to develop environmentally sound, energy inexpensive and well scalable drying techniques that maintain high quality of dried fruit, optimisation of integrated process (ultrasound and air-drying) in the production of dried apples was conducted. Selected quality parameters of fresh and dried apples (variety Goldparmâne) resulting from different duration of ultrasonic pre-treatment and air-drying were compared. Sugars were determined spectrophotometrically using an enzymatic method. Content of total phenols and flavonoids was determined spectrophotometrically with the Folin-Ciocalteau assay, while the antioxidant capacity was evaluated by using...

D-Amino Acids and Computer Vision Image Analysis: A New Tool to Monitor Hazelnuts Roasting?

M. Arlorio, J. D Coisson, F. Travaglia, M. Rinaldi, M. Locatelli, M. Gatti, A. Caligiani, A. Martelli

Czech J. Food Sci., 2009, 27(10):S30 | DOI: 10.17221/914-CJFS

The roasting process allows complex chemical reactions in foods leading the formation of the Maillard-related compounds, which are of fundamental importance for colour and aroma development in hazelnuts (Corylus avellana L.). Colour is a charming characteristic of roasted foods; despite of their fundamental role in organoleptic properties, the roasting allows accumulation of some potentially toxic technological contaminants, as showed in other matrices (e.g. acrylamide, furan and D-amino acids). Free and protein-bound D-amino acids (D-aa) in foods can origin by technological processing (their formation is pH, time, and temperature-dependent),...

Functional Perspective of Products from Pears cv. Pituralka

T. Požrl, K. Podgrajšek, J. Hribar, M. Simčič

Czech J. Food Sci., 2009, 27(10):S301-S303 | DOI: 10.17221/923-CJFS  

Pears cv. Pituralka are autochthon old cultivar from west Slovenian region and northern part of Italy, that were traditionally consumed as cooked or baked meals. In our study we developed new products and defined their nutritional value. Different thermical treatments (cooking and baking) were used for preservation of these products in sugar solution with or without an ascorbic or citric acid and packed in vacuum in a thermostable polyamide/polypropylene (PA/PP) foil. The products made from pears cv. Pituralka were sensory evaluated. The results show that Pituralka pears can be consumed only if they are thermally processed. Containing high amount of...

The Effects of non-Thermal Processing on Carotenoids in Orange Juice

M. J. Esteve, F. J. Barba, S. Palop, A. Frígola

Czech J. Food Sci., 2009, 27(10):S304-S306 | DOI: 10.17221/1094-CJFS  

New non-thermal technologies are emerging, such as pulsed electric fields (PEF) and high hydrostatic pressure (HHP), in order to provide a response to the need for greater nutritional and sensory quality in some manufactured foods in which the characteristics of freshness are especially affected by thermal treatments. The effect of non-thermal processing (PEF, 30 kV/cm, 100 μs and HHP, 4000 bars, 5 min) and pasteurisation (90°C, 20 s) on carotenoids of orange juice was studied. The total carotenoid concentration in the pasteurised juice (1195.4 ± 31.6 μg/100 ml) decreased significantly in comparison with the fresh juice (1367.2 ±...

Anteroxanthin Concentration during Refrigerated Storage in Orange Juice Treated by PEF

C. Cortés, M. J. Esteve, A. Frígola

Czech J. Food Sci., 2009, 27(10):S307-S309 | DOI: 10.17221/1083-CJFS  

Pulsed Electric Field (PEF) processing inactivates microorganisms without significant adverse effects on flavor and nutrients. In this work was studied the transformations of antheraxanthin and mutatoxanthin when natural orange juice is treated by pasteurisation (90°C, 20 s) or PEF (30 kV/cm, 100 μs), and also its evolution during seven weeks of storage in refrigeration at two different temperatures (2°C and 10°C). The results showed that antheraxanthin concentration decreased during the storage. The decrease was greater in the untreated, pasteurised and PEF-treated orange juices stored at 10°C and this carotenoid was not detected from the 6^th...

The Natural Products in Protection against the most Important Pathological Changes in Human Metabolism

M. Votruba, M. Vecka, L. Prokeš, B. Jurášková

Czech J. Food Sci., 2009, 27(10):S31-S34 | DOI: 10.17221/1095-CJFS  

Inflammation in joint: The liberation of phospholipids from cell membranes represents the first step of inflammation cascade. By action of phospholipase A2 is split of the arachidonic acid. Free arachidonic acid is than metabolised by two enzymes: 5-lipooxygenase and 2-cyclooxygenase to generate the group of prostanoids and leukotrienes which are the first active proinflammation compounds, starting the whole proces of inflammation. We verífied, that 27 flavonoids and flavans, contained in American patent Univestin are really able to interrupt this pathway by inhibition both of those enzymes. All these flavonoids are naturally occurring chemicals,...

Quality of Coloured Varieties of Potatoes

K. Hejtmánková, V. Pivec, E. Trnková, K. Hamouz, J. Lachman

Czech J. Food Sci., 2009, 27(10):S310-S313 | DOI: 10.17221/605-CJFS  

Coloured potatoes Solanum tuberosum L.) were evaluated as important source of natural antioxidants. Eight varieties of these potatoes (Salad Blue, Shetland Black, Blue Congo, Blaue St. Galler, Highland Burgundy Red, Violette, Valfi, Vitelotte) grown in four different locations in the Czech Republic (Přerov nad Labem, Suchdol, Valečov and Stachy) were analysed. Content of majority antioxidants (anthocyanins, chlorogenic acid and ascorbic acid) was determined and the obtained results were correlated with antioxidant activity. Total anthocyanin content and antioxidant activity were determined spectrophotometrically and phenolic acids by HPLC-DAD....

Factors Affecting the Softening of Pickled Pasteurised Cucumbers

M. Voldřich, I. Horsáková, M. Čeřovský, H. Čížková, H. Opatová

Czech J. Food Sci., 2009, 27(10):S314-S318 | DOI: 10.17221/1072-CJFS  

During the last three seasons the specific softening of pickled cucumbers was observed. The defective samples were analysed, but no microbial contamination was confirmed and no residual enzyme activity as well. The hypothesis of residual activity of microbial pectinases and cellulases as the most probable softening cause was proposed. The cellulolytic and pectolytic activities of nineteen strains of moulds and yeasts isolated from the samples of soils, cucumbers and cucumber plants rests were compared. The inactivation parameters (D and z values) of pectolytic enzymes of the most active strains were determined. The inhibitory effect of Ca²⁺...

Glucose, l-Malic Acid and pH Effect on Fermentation Products in Biological Deacidification

A. Kunicka-Styczyńska

Czech J. Food Sci., 2009, 27(10):S319-S322 | DOI: 10.17221/604-CJFS  

Industrial wine yeasts Saccharomyces cerevisiae Syrena, an interspecies hybrid (S. cerevisiae × S. bayanus) HW2-3 and Schizosaccharomyces pombe met 3-15 h^{+>/sup> were examined to determine changes in fermentation profiles in different environmental conditions in YG medium with different concentrations of glucose (2, 6, 40 or 100 g/l), L-malic acid (4, 7 or 11 g/l) and at pH 3.0, 3.5 and 5.0. The results were obtained by HPLC method (organic acids, acetaldehyde, glycerol, diacetyl) and enzymatically (L-malic acid, ethanol). In anaerobic conditions (100 g/l glucose), the optimal parameters for L-malic acid decomposition}...

A Contribution to Analysis of "Czech Beer" Authenticity

S. Obruča, I. Márová, K. Pařilová, L. Müller, Z. Zdráhal, R. Mikulíková

Czech J. Food Sci., 2009, 27(10):S323-S326 | DOI: 10.17221/1060-CJFS  

Total benefit effect of beer is a result of many individual contributions of natural substances present in such complicated biological material. Recently, regional mark "Czech beer" was obtained by EC. This beer is processed by traditional technology using only recommended brewery materials. Presented work is focused on proteomic and metabolomic analysis of some characteristic active substances specific for "Czech beer". Eight beer samples obtained from retail chain and/or from breweries were enrolled into this study. Polypeptides and proteins that influence beer sensory properties originated mainly from malt. The results of our preliminary study indicate...

Time-Intensity Studies of Sweeteners

K. Čmejlová, Z. Panovská, A. Váchová, D. Lukešová

Czech J. Food Sci., 2009, 27(10):S327-S329 | DOI: 10.17221/916-CJFS  

We used time-intensity studies in this work for evaluating the perception of sweet taste of sucralose, aspartame, and saccharose over time. In second part of this study the mixture of sweeteners and zinc sulphate, which modifies sweet taste perception, was used. We determined the following parameters from the assessor's charts of time profile: maximum intensity of sweet taste and the time which was needed to get to its maximum, the time period of perception of sweet taste and the area under the curve. For evaluation each assessor received 20 ml of a water solution with the sweetener followed by the mixture of the same sweetener with zinc sulphate....

The Selection of the Optimal Rate of Acid and Sweet Taste for Lemon Flavoured Drops

A. Váchová, Z. Panovská, D. Lukešová

Czech J. Food Sci., 2009, 27(10):S330-S332 | DOI: 10.17221/942-CJFS  

The objective of this work was to choose an optimal rate of citric acid and sweeteners for lemon flavoured drops. Two model samples with defined concentrations of citric acid and two commercial samples were evaluated with using instrumental and sensory methods. Concentrations of sweetening agents and citric acid in the samples were determined using HPLC with a RI detector and isotachophoresis, respectively. The general pleasantness of taste and the intensity of acid and sweet tastes of four lemon drops were evaluated using sensory analysis. General pleasantness was evaluated using a ranking test. Intensities of acid and sweet tastes were evaluated...

Sensitivity of Assessors to Ferrous Salts

Z. Panovská, A. Váchová, J. Řeřichová

Czech J. Food Sci., 2009, 27(10):S333-S336 | DOI: 10.17221/1082-CJFS  

Taste is the chemical sensation whose function is not very well known. Recently it was shown that the range of taste is more extensive than the five basic taste sweet, salty, bitter, sour and umami. A metallic taste has been suggested as another basic taste, but its mode of perception is not well understood and has not been really accepted in the taste literature. Ferrous sulphate solutions were presented to the assessors so their sensitivity and best estimate thresholds (BET) were measured. The best estimated threshold range was 0.00049-0.00669 g/l for demineralised water, 0.00079-0.00669 g/l for distilled water and 0.00108-0.00669 g/l for tap water.

Application of Fluorimetric Methods for Selected Additives Determination in Food Products

M. Kurzawa, A. Jastrzębska, E. Szłyk

Czech J. Food Sci., 2009, 27(10):S337-S339 | DOI: 10.17221/1070-CJFS  

Simple and sensitive spectrofluorimetric method for phosphorus determination in food samples after microwave mineralisation has been described. The proposed method is based on the formation of a fluorescent chelate between morin and aluminium and the fluorescence quenching after addition of phosphates solution. Additionally, the method with quinine sulphate was modified and applied for food samples. The proposed procedures were compared with respect of linearity, precision and accuracy.

Comparison of cITP and 31 P NMR Methods for Determination of Polyphosphates in Meat Product and Sea Fruits

A. Jastrzębska, P. Hrynczyszyn, E. Szłyk

Czech J. Food Sci., 2009, 27(10):S340 | DOI: 10.17221/919-CJFS

Phosphates are widely used as additives in different kinds of food, including meat, poultry and seafood. These ions work synergistically with salt and allow meat processors to achieve equivalent water-holding capacity with reduced amounts of salt. Polyphosphates added to meat and seafood products hydrolysed quickly to phosphates and it is difficult to estimation of these compounds (Davis et al. 2004; Sheard & Tali 2004; Jastrzębska et al. 2008). In our work we compared capillary isotachophoresis (cITP) and nuclear magnetic resonance (31P NMR) methods for phosphate ions determination in food samples. Furthermore, the usefulness of...

Chemically Modified Potato Starch as a Source of Nutritional and Non-nutritional Components

M. Wronkowska, U. Krupa-Kozak, M Soral-Śmietana

Czech J. Food Sci., 2009, 27(10):S341 | DOI: 10.17221/601-CJFS

Chemical modification of starch for food purposes is strictly limited in terms of the type of chemical reactions, the kind of modifying agents, the degree of substitution as well as the level of contaminants. Commonly applied chemical reactions include only three types, i.e. oxidation, esterification and etherification. Influence of chemicallymodified starches on a biological processes occurring in a human body seems to be interesting, especially as a source of the substances indispensable for the course of various metabolic processes. The study was aimed at answering a question: whether or to what extent the commercial preparations of potato starch,...

Improving Microwave Heating using Polysaccharides as Thickeners

L. M. Guardeño, M. Hernández-Carrión, J. M. Catala-Civera, P. Plaza, L. Pérez-Munuera, I. Hernando

Czech J. Food Sci., 2009, 27(10):S342-S345 | DOI: 10.17221/1085-CJFS  

The aim of this work was to improve microwave heating in white sauces using different polysaccharides in their formulation; ι-, λ- and κ-carrageenan and native and modified starches were used as thickeners. Five model systems were prepared, each one with a different polysaccharide, salt, and water. Dielectric loss factor (ε'') was measured and penetration depth of the electric field was calculated at 20 and 40°C at 2450 GHz. The results showed that ε'' increased significantly (P < 0.05) when temperature rose in all the model systems. Moreover, ε'' decreased significantly (P < 0.05) when...

Improving the Quality of Roasted Hazelnuts during their Shelf-life using Film Coating Starch-Based

F. Travaglia, J. D Coisson, M. Bordiga, A. Martelli, M. Arlorio

Czech J. Food Sci., 2009, 27(10):S346 | DOI: 10.17221/955-CJFS

The "film coating" is a process of depositing a thin layer edible transparent film of material onto a food, in order to provide a functional protective barrier covering its outer surface. The protective function of edible films and coating is to prevent the transfer of moisture, oxygen, flavour, and/or lipid content, between food and the surrounding medium and/or between different compartments in a heterogeneous food. Water-based coating suspensions are desirable to avoid the drawbacks of organic solvent-based coating suspensions. Starch can be used in coating technology; to overcome brittleness inherent of starch films, the incorporation of a plasticiser...

Effect of Packaging Films Releasing Antimicrobial Agents on Stability of Food Products

K. Hanušová, J. Dobiáš, K. Klaudisová

Czech J. Food Sci., 2009, 27(10):S347-S349 | DOI: 10.17221/958-CJFS  

The study was aimed to (I) test the effect of polyethylene (LDPE) films coated by commercially available polyvinylchloride (PVC) lacquer with addition of nisin preparation Nisaplin® (5% w/w) and/or natamycin preparation Delvocid^TM (10% w/w) on the growth of target bacteria, yeasts and moulds on the surface of soft cheese Blaťácké zlato produced by company Madeta, a.s., Veselí nad Lužnicí, and (ii) prepare and study the antimicrobial films with incorporated lactic acid or sodium lactate, suitable for packaging of raw chicken meat. The cheese in contact with nisin/natamycin treated film was stored at temperature 4°C and 23°C...

Plasma-oxidative Degradation of Polyphenolics - Influence of Non-thermal Gas Discharges with Respect to Fresh Produce Processing

F. Grzegorzewski, O. Schlüter, J. Ehlbeck, K.-D. Weltmann, M. Geyer, L. W. Kroh, S. Rohn

Czech J. Food Sci., 2009, 27(10):S35-S39 | DOI: 10.17221/1107-CJFS  

Non-thermal plasma treatment is a promising technology to enhance the shelf-life of fresh or minimaly processed food. An efficient inactivation of microorganisms comes along with a moderate heating of the treated surface. To elucidate the influence of highly reactive plasma-immanent species on the stability and chemical behaviour of phytochemicals, several polyphenolics were exposed to an atmospheric pressure plasma jet (APPJ). The selected flavonoids are ideal target compounds due to their antioxidant activity protecting cells against the damaging effects of reactive oxygen species such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals...

Nucleic Acid Lateral Flow Immunoassay for the Detection of Pathogenic Bacteria from Food

M. Blažková, M. Koets, J. H. Wichers, A. van Amerongen, L. Fukal, P. Rauch

Czech J. Food Sci., 2009, 27(10):S350-S353 | DOI: 10.17221/959-CJFS  

Nucleic acid lateral flow immunoassay (NALFIA) is a method combining molecular biological principle of detection with immunochemical principle of visualisation. Following isolation of DNA from the sample, a duplex PCR with two primer sets, of which one was labelled with biotin and the other with digoxigenin or fluorescein, respectively, was performed. The PCR solution and carbon particles conjugated with avidin are directly added to the nitrocellulose membrane with two test lines of immobilised antibodies specific for digoxigenin and fluorescein. The appearance of a black line indicates the presence of specific amplicon. We would like to present the...

Importance of Enterococcus spp. for Forming a Biofilm

L. Necidová, B. Janštová, S. Karpíšková, Š. Cupáková, M. Dušková, R. Karpíšková

Czech J. Food Sci., 2009, 27(10):S354-S356 | DOI: 10.17221/1087-CJFS  

The aim of this study was to monitore the capability of Enterococcus fecalis and Enterococcus fecium to form biofilms. Enterococci isolates originated from individual milk, bulk milk samples and environmental swabs obtained at farm level, dairy plant level including semi and final dairy products. Biofilm formation potential was determined by growing the tested strains in glas tubes containing BHI medium. The capability of forming biofilms was detected in 28% of Enterococcus spp. strains. Higher number of biofilm forming strains of the Enterococcus faecium (33%) than Enterococcus faecalis (28%) has been registered....

Tyramine Production by Enterococci from Various Foodstuffs: A Threat to the Consumers

K. Trivedi, I. Borkovcová, R. Karpíšková

Czech J. Food Sci., 2009, 27(10):S357-S360 | DOI: 10.17221/934-CJFS  

Tyramine is the most frequent biogenic amine found in cheese and is also frequently found in other fermented foods and beverages. In total 273 different strains of enterococci from various foodstuffs were studied. A multiplex PCR was designed for the genotypic differentiation of various enterococci strains at species level and for determination of the presence of tyramine producing (tyrdc) gene. E. faecalis and E. faecium were found to be prominent strains in dairy and meat products while, E. faecium and E. mundtii were found to be ruling in case of fruits and vegetables. HPLC analysis was carried out for determination...

Aflatoxins and Ochratoxin A in Red Paprika for Retail Sale in Spain: Occurrence and Evaluation of a Simultaneous Analytical Method

J. M Hernández-Hierro, R. J Garcia-Villanova, P. Rodríguez Torrero, I. M Toruño Fonseca

Czech J. Food Sci., 2009, 27(10):S361 | DOI: 10.17221/961-CJFS

Aflatoxins are well-known mycotoxins produced mainly by two Aspergillus species particularly abundant in areas of the world with hot, humid climates. Aspergillus flavus, which is ubiquitous, produces B aflatoxins. A. parasiticus which produces both B and G aflatoxins, has more limited distribution. The next most studied mycotoxin is ochratoxin A. It belongs to a group of five produced by Penicillium verrucosum and by several species of Aspergillus, most notably A. ochraceus. Contamination of red pepper spice by aflatoxins and ochratoxin A may occur at any stage of production, from preharvest to drying and storage....

Asaia sp. as a Bacterium Decaying the Packaged Still Fruit Beverages

I. Horsáková, M. Voldřich, M. Čeřovský, P. Sedláčková, P. Šicnerová, P. Ulbrich

Czech J. Food Sci., 2009, 27(10):S362-S365 | DOI: 10.17221/970-CJFS  

Several cases of consumer complaints to the still soft beverages - fruit drinks and ice teas were analysed. The visible impurities and slight sensory changes were observed, sediment was formed by microbial cells. The bacteria were isolated and identified as Asaia sp. The identification was confirmed by PCR technique. The sensitivity of bacteria to preservative agents especially to the sodium benzoate, potassium sorbate and dimethyldicarbonate was evaluated in model samples and in the real conditions of the beverage. The minimal inhibitory concentrations were estimated as well as the factors affecting the sensitivity of bacteria. Besides the...

Searching for Genes of Lactococcus lactis subsp. lactis Encoding the Bacteriocin Nisin using DNA/DNA Hybridisation

M. Dušková, A. Španová, V. Dráb, B. Rittich

Czech J. Food Sci., 2009, 27(10):S366-S368 | DOI: 10.17221/603-CJFS  

In this work, PCR primers P8 and P9 were used for amplification of a 320 bp long PCR product specific to the nisin gene. The PCR product was labelled with digoxigenine during amplification and used as a DNA probe for the screening of homologous DNA sequences in 7 Lactococcus lactis subsp. lactis strains from the Culture Collection of Dairy Microorganisms (CCDM). Dot blot hybridisation and hybridisation of colonies were used for DNA/DNA hybridisation. It was shown that 6 tested strains of Lactococcus lactis subsp. lactis have genes encoding nisin. One strain had probably a defective gene encoding nisin.

Methods for the Determination of Allergenic Substances in Foods

K. Tomková, F. Štumr, P. Dvorská, P. Šafářová, J. Rysová, D. Gabrovská, P. Hanák, J. Plicka

Czech J. Food Sci., 2009, 27(10):S369-S371 | DOI: 10.17221/945-CJFS  

Within the framework of the research project ELISA methods for the quantitative determination of allergenic substances in foodstuff and raw materials were developed. ELISA kits for allergenic proteins of milk (casein, beta-lactoglobulin and BSA) egg white proteins and mustard proteins were validated and collaborative studies were performed to prove the validation of the ELISA methods developed. Various methods of extraction were tested. The parameters as a limit of detection, as a limit of quantification, robustness, repeatability and accuracy were determined. A broad range of zero matrices for allergens were tested as well. The ELISA kits are suitable...

Influence of Type of Substrate and Enzyme Concentration on Formation of Galacto-oligosaccharides

K. Hellerová, L. Čurda

Czech J. Food Sci., 2009, 27(10):S372-S374 | DOI: 10.17221/960-CJFS  

Different substrates and different concentrations of enzyme (Maxilact LX 5000) for galacto-oligosaccharides synthesis were tested. Lactose in phosphate buffer (138 mmol/l), ultrafiltration permeate (115 mmol/l), recombined whey (136 mmol/l) were used as substrates. Concentrations of used enzyme were from 0.15 to 15 U/ml for lactose in buffer, from 0.12 U/ml to 1.5 U/ml for ultrafiltration permeate and 1.5 U/ml for recombined whey. Reaction products were analysed by HPLC. There was obtained 6.4 ± 0.4 mmol/l of galacto-oligosaccharides (GOS) for lactose in buffer, it means that 0.0633 ± 0.0025 g/g of lactose was converted to GOS. The conversions...

Cyanogenic Potential of Roasted Cassava (Manihot esculenta Crantz) roots Rale from Inhambane Province, Mozambique

L. Tivana, J. Da Cruz Francisco, B. Bergenståhl, P. Dejmek

Czech J. Food Sci., 2009, 27(10):S375-S378 | DOI: 10.17221/1102-CJFS  

Roasted cassava roots flour is part of a common meal in Africa, it is known as rale in Mozambique. Fifty six samples of rale were collected from homes and markets in Inhambane Province, Mozambique, for cyanogenic potential (CNp) analyses. The names of cassava varieties used for preparing the rale samples could be determined in the home-collected samples, three varieties were recorded. Xinhembwe variety gave rale samples with 30 ± 8 mg CNp/kg (mean + standard error), Precoce de angola with 43 ± 11 mg CNp/kg and Rungo sabonete with 58 ± 22 mg CNp/kg dry weight. The mean cyanogenic value...

Off-flavour Defects of Packed Waters and Soft Drinks

H. Čížková, M. Voldřich, R. Ševčík, J. Pivoňka

Czech J. Food Sci., 2009, 27(10):S379-S381 | DOI: 10.17221/1090-CJFS  

Greases and lubricants, organic cleaning agents and other material which are used for the maintenance of technological equipment belong to the important potential sources of off-flavours in packed water because of higher risk of misuse or fault of the staff. A simple, efficient and sensitive method of SPME/GC/MS together with descriptive sensory analysis have been used to analyse the sensory defect. The real case study of the consumer complaint to the PET bottled spring water was solved, the defective products exhibited the organic, petroleum, hydrocarbon taint, the complaints were about twenty bottles of one batch. Aroma profiles of all maintenance...

Contents of Heavy Metals in Different Saccharides Fractions of Potato Tubers

J. Musilová, T. Tóth, J. Árvay

Czech J. Food Sci., 2009, 27(10):S382-S385 | DOI: 10.17221/1067-CJFS  

In this work the Cd, Cu and Zn accumulation in potatoes, their influence on starch, water-soluble (WSS) and water-insoluble saccharide (WIS) contents and content of heavy metals in various saccharide fractions of potatoes were determined. The fraction of WSS was isolated by Somogyi method, the WIS fraction was obtained from delipided portion of potatoes. Enhanced pseudototal Cd contents in relationship to limit value 0.7 mg/kg of soil were determined in 13 soil samples (0.72-1.06 mg/kg). Contents of Zn and Cu were lower than their limit values in all observed soil samples. Observed heavy metals have not influence on their accumulation in potatoes,...

Effect of Heavy Metal Treatment on Molecular Changes in Root Tips of Lupinus luteus L.

K. Jomová, M. Morovič

Czech J. Food Sci., 2009, 27(10):S386-S389 | DOI: 10.17221/602-CJFS  

Heavy metals cause changes either in the pattern of cellular stress protein expression or in the enzyme activity. In the present study, the effect of three different toxic element treatments (heavy metals Pb, Cd and metaloid As) on small heat shock proteins synthesis as well as the superoxide dismutase (SOD) activity in root tips of yellow lupine (Lupinus luteus L., varieta Juno) was studied. Solutions with four different concentrations from each salt [Pb(NO₃)₂, Cd(NO₃)₂ and As₂O₃] were applied to achieve ascending oxidative stress conditions in comparison to unstressed, water...

The Transfer of Heavy Metals from Contaminated Soils into Agricultural Plants in High Tatras Region

T. Tóth, J. Tomáš, P. Lazor, D. Bajčan, K. Jomová

Czech J. Food Sci., 2009, 27(10):S390-S393 | DOI: 10.17221/600-CJFS  

The problems of soil hygiene and contents of the following heavy metals: cadmium, cobalt and nickel in the productive parts of plants in the location of Agricultural Cooperative Štrba in Poprad County were discussed in the presented work. Above-mentioned location is found in the neighbourhood with a chemical factory Chemosvit Svit. The achieved results show that the soil hygiene in this region is mainly affected by the activity of this chemical factory. This factory is producing many risky substances and their results can be seen in the condition of soil hygiene and in the quality of farmed plants. The results of monitored heavy metals (Cd, Co, Ni)...

The Effect of Fertilisation Method on Selected Elements Content in Tomatoes (Lycopersicon lycopersicum)

I. Poustková, L. Kouřimská, K. Václavíková, D. Miholová, L. Babička

Czech J. Food Sci., 2009, 27(10):S394-S396 | DOI: 10.17221/599-CJFS  

Fermented pig slurry was used for two kinds of tomatoes fertilisation as a replacement of industrial mineral fertilisers in three-year experiment and selected elements (Pb, Cd, As, Zn and Hg) content were monitored by the AAS method. The results obtained showed that anaerobically fermented pig slurry can be a suitable alternative to mineral fertiliser use. Its use as an organic fertiliser also did not decrease the hygienic quality and safety of the grown vegetable products, and all tomato samples fulfilled the heavy metals legislation limits for Pb, Cd, As, Zn and Hg content. Statistically significant (P < 0.05) influences of the year, cultivar...

Monitoring of Risky Elements in Zone of Pollution Strážske Area

J. Tomáš, J. Čéry, S. Melicháčová, J. Árvay, P. Lazor

Czech J. Food Sci., 2009, 27(10):S397-S400 | DOI: 10.17221/598-CJFS  

The work aimed to evaluate the state of agricultural soil contamination what is important for the gaining of information needed for growing of hygienic safe raw materials and foodstuffs. Metallic pollution of soil in Zemplínska polluted area has begins by accumulation of heavy metals in soil, mainly resulting from location in vicinity of chemical and industrial factories, as well as from many others sources. The pH value development indicates gradual trend of soils acidification, except of alkalic ones reaching up to 20% from total arable soils in Slovakia. Acidification is process, where acidity of abiotic compounds has been increased. Soil reaction...

Characterisation of Whey Proteins-Pectin Interaction in Relation to Emulsifying Properties of Whey Proteins

R. Kováčová, A. Synytsya, J. Štětina

Czech J. Food Sci., 2009, 27(10):S4-S8 | DOI: 10.17221/632-CJFS  

The aim of this work was to characterise influence of whey proteins-pectin interaction on emulsification properties of whey. As the first, structural characteristics of pectin-protein complexes were evaluated for pure β-lactoglobulin by both dynamic light scattering method for measuring of the particle size distributions and Doppler laser electrophoresis for measuring the ξ-potential (surface electrical potential) of particles. In mixed pectin-β--lactoglobulin systems, it was observed that the addition of pectin prevent from the protein-protein interaction, which caused production of huge protein aggregates (2000-2500 nm) at pH values...

Aroma Formation during Thermal Food Processing: Why do Thermally Treated Foods Smell Differently?

P. Schieberle

Czech J. Food Sci., 2009, 27(10):S40 | DOI: 10.17221/953-CJFS

During thermal processing of foods non-volatile precursors undergo various types of reactions leading to the unique aromas of well-accepted product such as cocoa, coffee, cereals or nuts. It is without doubt that the reaction between free amino acids and carbohydrates or their degradation products, known as the Maillard reaction, is among the most important "flavor delivery" systems in such foods. However, studies using approaches of "molecular sensory science" have shown that the majority of the Maillard-type reaction products, identified so far, do not show a contribution to the aroma of processed foods. In addition, many of the key Maillard aroma...

Influence of Vintage on Cu, Fe, Zn and Pb Content in Some Croatian Red Wines

M. Banović, J. Kirin, N. Ćurko, K. Kovačević Ganić

Czech J. Food Sci., 2009, 27(10):S401-S403 | DOI: 10.17221/597-CJFS  

Knowledge of the content of heavy metals is important because of their impact on the wine stability or on the health of the consumers. The presence of heavy metals in wines is a consequence of an action of various factors such as conditions of the cultivation and processing of grapes and production, stabilisation or storage of wine. In this work determination of heavy metals (Cu, Fe, Zn and Pb) content in red wines was carried out. Selected wine was Plavac mali, Croatian autochthonous sort, produced by various producers during the three consecutive vintages. The aim of this work was to examine whether the wines produced in different vintage, and by...

Determination of Arsenic in the Rainbow Trout Muscle and Rice Samples

V. Harkabusová, 2^*, B. Macharáčková, O. Čelechovská, E. Vitoulová

Czech J. Food Sci., 2009, 27(10):S404-S406 | DOI: 10.17221/1078-CJFS  

The content of arsenic was determined in the rainbow trout muscle (Oncorhynchus mykiss) and in rice samples. The method of atomic absorption spectrometry with hydride generation (HG-AAS) in graphite furnace was used for total arsenic determination. Arsenic speciation was done using the high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS). The rainbow trout muscle was extracted by ultra pure deionised water; trifluoroacetic acid was used for the extraction of rice samples. Total arsenic values ranged from 60.90 μg/kg to 310.00 μg/kg in rice samples and from 0.72 mg/kg to 2.23 mg/kg in...

Determination of Tin in Canned Foods by Atomic Absorption Spectrometry

J. Knápek, V. Herman, R. Buchtová, D. Vošmerová

Czech J. Food Sci., 2009, 27(10):S407-S409 | DOI: 10.17221/1068-CJFS  

Atomic absorption spectrometry is a powerful technique for determination of tin in canned foods. Homogenous samples of syrup and solid parts were digested by means of microwave digestion system MLS 1200 MEGA where hydrochloric and nitric acid were used as reagents. The measurements were carried out using a Perkin-Elmer AAnalyst 700 atomic absorption spectrometer. Detection limit was 4 mg/kg in nitrous oxide and acetylene flame. There were analysed 222 samples of 26 various kinds of canned fruit (e.g. pineapple, peach, mandarin), vegetables (e.g. bean, mushroom, tomato) and meat (sea products) in this work. The analytical results indicated tin total...

Antioxidant Stability of Phenolic Acids and Their Esters

I. Hrádková, J. Šmidrkal, V. Filip, R. Merkl, E. Kabrdová

Czech J. Food Sci., 2009, 27(10):S41 | DOI: 10.17221/626-CJFS

Natural antioxidants found in plants play an important role in food and cosmetics because there is a trend to use this type of antioxidants. Phenolic acids (hydroxy derivatives of benzoic and cinnamic acids) are well soluble in various systems containing water, however, in bulk oils are limited soluble. Esters of phenolic acids are suitable antioxidants for bulk oil systems. The oxidative stability of the bulk oil systems with selected phenolic acids and their esters was determined by method Rancimat and Oxidgraph and compared with α-tocopherol and butylhydroxytoluene (BHT). The antioxidant activity of gentisic acid, caffeic acid and methyl caffeate...

Effect of Some Factors on the Biogenic Amines and Polyamines Content in Blue-Veined Cheese Niva

E. Standarová, I. Borkovcová, M. Dušková, H. Přidalová, M. Dračková, L. Vorlová

Czech J. Food Sci., 2009, 27(10):S410-S413 | DOI: 10.17221/965-CJFS  

We evaluated the effect of some factors (batch, producer, storage and amine distribution in cheese) on the biogenic amines and polyamines contents and microbial counts (Enterobacteriaceae, enterococci, lactic acid bacteria) in blue-veined cheese Niva. The tyramine content was increasing (P < 0.01) with storage time; at storage day 29, it reached 298 mg/kg and exceeded the toxicological limit. Cadaverine and the sum of biogenic amines also increased significantly (P < 0.01) and the latter reached up to 900 mg/kg, i.e. the established toxicological limit. The contents of the quantitatively most important biogenic amines (tyramine...

Pesticides in Food - Immunochromatographic Detection of Thiabendazole and Methiocarb

Z. Šmídová, M. Blažková, L. Fukal, P. Rauch

Czech J. Food Sci., 2009, 27(10):S414-S416 | DOI: 10.17221/1100-CJFS  

In this work preliminary studies on application of immunochromatographic method to detection of pesticides in food samples, in particular fruit juices, are presented. The aim was to develop immunochromatographic technique on a porous membrane for rapid detection of the pesticides thiabendazole and methiocarb in fruit juices. For detection colloidal carbon conjugated with secondary antibody was used. The tests were evaluated visually. Our results show that in the fruit juices samples examined the detection limit for thiabendazole covered the MRL (maximum residue limit) for food of plant origin established by the legislative and for methiocarb the method...

Analysis of Bread Lipids for 3-MCPD Esters

M. Doležal, J. Kertisová, Z. Zelinková, J. Velíšek

Czech J. Food Sci., 2009, 27(10):S417-S420 | DOI: 10.17221/932-CJFS  

Objective of this work was determination of processing contaminant known as 3-MCPD (3-chloropropane-1,2-diol) in its free and bound form in breads with defined parameters of processing. Selected and analysed were 24 samples, which represented two sets of breads produced in bakeries equipped with a continual line. In all cases determinations were carried out for breadcrumb and crust separately. The first set of samples were wheat-rye breads produced chronologically in ten days in the bakery Michelská pekárna, slightly different in temperatures and times of baking. The second set contained 14 samples of wheat-rye breads with a content of rye flour less...

3-Chloropropane-1,2-diol Fatty Acid Esters in Potato Products

Z. Zelinková, M. Doležal, J. Velíšek

Czech J. Food Sci., 2009, 27(10):S421-S424 | DOI: 10.17221/1065-CJFS  

The occurrence of 3-chloropropane-1,2-diol fatty acid esters (bound 3-MCPD) in French fries and potato chips is reported. These products belong to the group of foodstuffs with high amount of 3-MCPD esters. Bound 3-MCPD was determined in all analysed samples in following concentrations: pre-frying French fries 27-64 μg/kg, French fries (final product) 100-258 μg/kg and potato chips 229-1008 μg/kg. Palm oil used for frying potato chips was analysed as well and the bound 3-MCPD levels ranged from 654 to 1920 μg/kg. 3-MCPD esters are formed in these products as a consequence of the processing technique. Especially frying oil represents the...

Effect of Inorganic Salts on Acrylamide Formation in Cereal Matrices

K. Kukurová, Z. Ciesarová, A. Bednáriková, L. Marková

Czech J. Food Sci., 2009, 27(10):S425-S428 | DOI: 10.17221/956-CJFS  

The aim of the work was to compare the impact of different salts such as monovalent and divalent chlorides, hydrogencarbonates, phosphates and lactate on acrylamide formation in cereal model system during baking at 190°C for 9 min. Ammonium hydrogencarbonate promoted acrylamide production significantly. On the other hand, other inorganic salts lowered acrylamide content. Calcium chloride was the most effective with near to 90% acrylamide elimination ability. Sodium acid pyrophosphate, sodium as well as potassium dihydrogen phosphate were also very effective and brought about 75% acrylamide content decrease, followed by calcium lactate, sodium chloride...

Migration of Printing Ink Constituents from Packaging into Food Simulan

Z. Dupáková, K. Klaudisová, L. Votavová, J. Dobiáš, M. Voldřich

Czech J. Food Sci., 2009, 27(10):S429 | DOI: 10.17221/1098-CJFS

Printing inks contain many substances, the use of which is not allowed in food contact materials. Recently the migration of printing ink constituents from the printed packaging materials into food either through the packaging material or via the set-off phenomenon has been reported. The aim of presented study was to quantify the transfer of selected printing ink plasticisers, i.e. acetyl tributyl citrate (TBAC), bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) phthalate (DEHP), 2-ethylhexyl diphenyl phosphate (EHDPP) and tributoxyethyl phosphate (TBEP), from printing of packaging materials into food simulants. Two polymer packaging films, i.e. polyethylene...

Antioxidant Activity in Variously Prepared Elderberry Foods and Supplements

K. Cejpek, I. Maloušková, M. Konečný, J. Velíšek

Czech J. Food Sci., 2009, 27(10):S45-S48 | DOI: 10.17221/951-CJFS  

Antioxidant capacity of foods and food supplements based on berries and flowers of medicinal plant elderberry (Sambucus nigra L.) was assessed. Reducing properties of the samples and extracts were evaluated using amperometric detection at working electrode potential -0.8 V after HPLC separation. Moreover, antiradical activity of selected samples was determined by the means of spectrophotometric DPPH radical scavenging method. Electrochemical activity (EA) of fresh juice pressed from elder fruits amounted to 0.71 g AAE/l with anthocyanins as minor contributors (10.2%). Catechins and phenolic acids were the major active groups. During production...

Changes of Antioxidant Capacity of Robusta Coffee during Roasting

L. Votavová, M. Voldřich, R. Ševčík, H. Čížková, J. Mlejnecká, M. Stolař, T. Fleišman

Czech J. Food Sci., 2009, 27(10):S49-S52 | DOI: 10.17221/1105-CJFS  

The in vitro radical scavenging capacity of the roasted and ground coffee is generally known as well as the published results of lowering the incidence of various diseases by regular intake of coffee. The antioxidant capacity of coffee is based mainly on the phenols, but during the roasting phenols are degraded and new products with antioxidant capacity are formed. A major contributor to the antioxidant activity was identified as N-methylpyridinium, which is formed during the roasting by degradation of trigonelline, the degradation is about 50% of trigonelline content and the concentration of N-methylpyridinium in roasted coffee is up to 0.25%...

Effect of Germination Conditions on Antioxidant Activity of Germinated Brown Rice

A. Jongjareonrak, R. Sawaddiwong, S. Benjakul, K. Osako, M. Tanaka

Czech J. Food Sci., 2009, 27(10):S53 | DOI: 10.17221/905-CJFS

This investigation aims to study the effects of germination conditions and extraction solvents on total phenolic content and antioxidant activities of Chiang Phatthalung a recommended rice cultivar in Southern Thailand. Chiang Phatthalung (Oryza sativa L.) was germinated by soaking in tap water at 25, 30, 35 or 40°C for 24 h and then dried and powderised before subjected to extract with various solvents and analyses. Amongs all extraction solvents used, including 50% MeOH + 0.1% HCl, water, 25% EtOH, 50% EtOH, 75% EtOH and 95% EtOH, rices extracted with 50% EtOH had highest total phenolic content and antioxidant activities (P < 0.05)....

Advances in the Understanding of the Chemical Reactions Responsible for Bread Flavour Quality

P. Poinot, G. Arvisenet, J. Grua-Priol, C. Fillonneau, S. Mezaize, M. De Lamballerie, A. Le-Bail, C. Prost

Czech J. Food Sci., 2009, 27(10):S54-S57 | DOI: 10.17221/1074-CJFS  

This work aimed at analysing bread extracts obtained under headspace and artificial mouth conditions in order to study the reactions responsible for bread flavour quality. Selected extraction conditions were first compared according to the odour and aroma representativeness of the bread extracts. The optimal conditions were then applied to extract volatiles of a conventional gluten bread formulation and an innovative gluten-free bread formulation. Results reveal that an extraction duration of 10 min in the artificial mouth was sufficient to obtain a representative aroma extract. Yet, 30 min of headspace extraction were necessary to obtain a representative...

Release of Strawberry Aroma Compounds by Different Starch-Aroma Systems

R. Vidrih, E. Zlatić, J. Hribar

Czech J. Food Sci., 2009, 27(10):S58-S61 | DOI: 10.17221/912-CJFS  

In the food industry, the addition of flavours is used to reinforce the aroma profile of different goods. However, interactions between starch and aroma compounds can occur, and this can impact upon aroma release and perception. In the present study, we have investigated the influence of starch type on aroma release from starch-aroma systems. The food model system used was composed of an aqueous starch dispersion (1 g dry starch/100 g dispersion) and 10 aroma compounds (ethyl butanoate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl pentanoate, methyl hexanoate, ethyl hexanoate, methyl ethyl propanoate, hexyl acetate, 3-hexenol, and phenyl...

Effect of Closure, Packaging and Storage Conditions on Impact Odorants of Wine

G. J. Pickering, A. Blake, Y. Kotseridis

Czech J. Food Sci., 2009, 27(10):S62-S65 | DOI: 10.17221/1104-CJFS  

3-alkyl-2-methoxypyrazines (MPs) represent an important and potent class of odor-active compounds associated with wine quality. 30 ng/l each of 3-isobutyl-2-methoxypyrazine, 3-isopropyl-2-methoxypyrazine and 3-secbutyl-2-methoxypyrazine were added to a Riesling and Cabernet Franc wine and monitored with HS-SPME-GC-MS over 18 months to investigate the effects of various closure and packaging options as well as light and storage temperature on MPs. Other impact odorants were monitored using SPE-GC-FID. Changes in MP concentrations during bottle aging varied with closure/packaging option, with the greatest decrease evident in Tetrapak® cartons. We...

Dietary Maillard Reaction Products: Implications for Human Health and Disease

J. M. AMES

Czech J. Food Sci., 2009, 27(10):S66-S69 | DOI: 10.17221/624-CJFS  

When foods are heat processed, the sugars and lipids react with the proteins they contain via the Maillard and related reactions to form a wide range of products. As a result, the sensory, safety, nutritional and health-promoting attributes of the foods are affected. Reaction products include advanced glycation/lipoxidation endproducts (AGE/ALEs), acrylamide and heterocyclic amines (HAA), all of which may impact on human health and disease. Furthermore, some Maillard reaction products affect the growth of colonic bacteria and thermally-induced modification of dietary protein can affect allergenicity. This paper briefly reviews aspects of the Maillard...

Complementary Advanced Techniques Applied for Plant and Food Authentication

C. Socaciu, F. Ranga, F. Fetea, L. Leopold, F. Dulf, R. Parlog

Czech J. Food Sci., 2009, 27(10):S70-S75 | DOI: 10.17221/1071-CJFS  

Our studies focus on the characterisation of specific metabolic profiles of some representative plants from Romania (St. John wort, soybean and seabuckthorn berries) and their derived products (oils, hydrophilic and lipophilic extracts) with biomedical and food applications. Four different, complementary methods were applied successively: UV-Vis and FTIR spectroscopy versus chromatography (HPLC-PDA, GC-FID). To investigate accurately the main biomarkers specific to each plant tissue (secondary metabolites) or to final products were determined as useful quality and authenticity indicators: carotenoid pigments, phenolic derivatives and flavonoids, fatty...

The Changes of α+-Galactosides during Germination and High Pressure Treatment of Legume Seeds

J. Dostálová, P. Kadlec, J. Bernášková, M. Houška, J. Strohalm

Czech J. Food Sci., 2009, 27(10):S76-S79 | DOI: 10.17221/1076-CJFS  

The α-galactosides negatively affect of grain legumes digestibility. The most effective way of α-galactosides content decreasing is germination. The contents of αα-galactosides in legume seeds were decreased by germination up to 16% of original value (lentil). During the germination, the contents of microorganisms are arising to high values. The effective method for decreasing of microorganisms content is high pressure treatment. During the high pressure treatment (500 MPa for 10 min) the further α-galactosides are decomposed up to 5% of original value (mung bean). The contents of α-galactosides in high pressure...

Effect of Sulphur Fertilisation on Lycopene Content and Colour of Tomato Fruits

E. Zelená, M. Holasová, F. Zelený, V. Fiedlerová, P. Novotná, A. Landfeld, M. Houška

Czech J. Food Sci., 2009, 27(10):S80-S84 | DOI: 10.17221/915-CJFS  

The effects of different sulphur (S) fertilisers (ammonium, sodium, potassium and calcium sulphates) in combination with nitrogen (N) on plant growth, yield and quality of fruits were investigated in two dwarf cultivars Proton and Šejk. Single N, applied as ammonium nitrate, stimulated growth of plants and significantly increased yield of fruits, but did not change content of lycopene as well as colour parameters (a*, b* and L*) and decreased significantly S content in fruits. All S fertilisers significantly increased S and lycopene content in fruits (up to 39% in cv. Šejk and 92% in cv. Proton) and positively influenced colour of tomato...

Differences in Thermal Stability of Glucosinolates in Five Brassica Vegetables

M. Dekker, K. Hennig, R. Verkerk

Czech J. Food Sci., 2009, 27(10):S85-S88 | DOI: 10.17221/1079-CJFS  

The thermal stability of individual glucosinolates within five different Brassica vegetables was studied at 100°C for different incubation times up to 120 minutes. Three vegetables that were used in this study were Brassica oleracea (red cabbage, broccoli and Brussels sprouts) and two were Brassica rapa (pak choi and Chinese cabbage). To rule out the influence of enzymatic breakdown, myrosinase was inactivated prior to the thermal treatments. The stability of three glucosinolates that occurred in all five vegetables (gluconapin, glucobrassicin and 4-methoxyglucobrassicin) varied considerably between the different vegetables. The degradation...

Masked Mycotoxins: an Emerging Issue for Food Safety

G. Galaverna, C. Dall'Asta, M. Mangia, A. Dossena, R. Marchelli

Czech J. Food Sci., 2009, 27(10):S89-S92 | DOI: 10.17221/1064-CJFS  

The presence of masked or hidden forms of Fusarium mycotoxins (deoxynivalenol, DON, zearalenone, ZEN and fumonisins B1, B2 and B3) were studied in wheat and maize derived products. Significant amounts of these forms were found both in raw and in processed food commodities. Deoxynivalenol-3-glucoside was found in wheat products up to 30% of DON concentration. Bound forms of fumonisins often account for an equal or even higher amount in comparison with the free forms.

Antioxidants in Margarine Emulsions

V. Filip, I. Hrádková, J. Šmidrkal

Czech J. Food Sci., 2009, 27(10):S9-S11 | DOI: 10.17221/1089-CJFS  

The lipid oxidation in margarine takes place in continuous liquid oil phase. The extension of fat interfaces in the system - emulsion of water in oil and the dispersion of fat crystals in liquid oil influences on the peroxidation, decomposition of hydroperoxides to aldehydes and the oxidative stability in the comparison with oxidation in the fat blend. Different antioxidants were used in margarine dispersions: L(+)ascorbic acid, ascorbyl palmitate and DL-α -tocopherol. Increasing polarity and decreasing molecular size of antioxidants have the positive influence on lipid oxidation: DL-α-tocopherol is the least effective antioxidant...

Effects of Formulation and Baking Conditions on Neo-formed Contaminants in Model Cookies

M. Courel, L. Ait-Ameur, E. Capuano, V. Fogliano, F. J. Morales, F. Courtois, I. Birlouez-Aragon

Czech J. Food Sci., 2009, 27(10):S93-S95 | DOI: 10.17221/954-CJFS  

This work aimed at studying the influence of baking temperature and formulation on the formation of undesirable Maillard compounds called neoformed contaminants (NFC) in a model cookie system. Four NFCs were observed as furosine (FUR), carboxymethyllysine (CML), hydroxymethylfurfural (HMF) and acrylamide (ACR) for three baking temperatures - 150, 200 and 230°C - and three recipe variables as sugar type, fat saturation level and leavening agent. The results showed significant accumulation of all neoformed contaminants along baking with specifically strong temperature dependence for HMF and ACR while CML and FUR were more time dependent. The type of...

Improvement of Cereal Product Safety by Enzymatic Way of Acrylamide Mitigation

Z. Ciesarová, K. Kukurová, A. Bednáriková, L. Marková, S. Baxa

Czech J. Food Sci., 2009, 27(10):S96-S98 | DOI: 10.17221/1061-CJFS  

Acrylamide as a probably carcinogenic compound is known to be formed in many high thermally treated products with a natural occurrence of amino acid asparagine and reducing sugars as well. Cereal products, especially gingerbreads are extensively affected by acrylamide formation up to 1000 μg/kg and more. This study compares pros and cons of enzyme treatment and a substitution of ammonium raising agent for sodium salt addition in manufactured gingerbreads with respect to their final sensory quality. More than 97% reduction of acrylamide content was achieved by the asparaginase application before baking with no observed detrimental effect on sensory...

Studies on Enzymatic Crosslinking of Casein Micelles

C. Partschefeld, J. Schreiner, U. Schwarzenbolz, T. Henle

Czech J. Food Sci., 2009, 27(10):S99-S101 | DOI: 10.17221/938-CJFS  

The aim of our study was to gain insights into the reactions occurring in casein micelles during enzymatic modification with microbial transglutaminase (mTG). Therefore, UHT-treated milk was incubated with varying amounts of mTG and the caseins were analysed using different analytical methods. Regarding the casein species, it was observed that β -casein was crosslinked to a higher extent than the α-caseins. From this it can be suggested that β-casein is mainly located in the outer space of the micellar structure and therefore better accessible to mTG than α-caseins, which are located predominantly in the interior. Furthermore,...

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