Czech Journal of Food Sciences, 2015 (vol. 33), issue 5
Phenolic amides (avenanthramides) in oats - a reviewReview
Hüseyin BOZ
Czech J. Food Sci., 2015, 33(5):399-404 | DOI: 10.17221/696/2014-CJFS 
Whole grain cereals such as oats are important sources of phenolic compounds. Oats contain phenolic amides, also named avenanthramides (AVAs), which have beneficial health properties because of their antioxidant, anti-inflammatory, and antiproliferative effects. The most common avenanthramides are esters of 5-hydroxyanthranilic acid with p-coumaric (AVA-A), ferulic (AVA-B), or caffeic (AVA-C) acids. The studies related to the stability of AVAs showed that AVA-B is sensitive to alkaline and neutral conditions and this sensitivity increases with higher temperatures. However, has been reported that AVA-A and AVA -C are more stable under the same...
The "Breme" red onion: effects of home-storage methods on quercetin and quercetin-glycoside contentsFood Chemistry and Safety
Elena DOZIO, Alessandra BARASSI, Alessandro RAVELLI, Ilaria ANGELI, Franco LODI, Gian Vico MELZI d'ERIL, Massimiliano M. CORSI ROMANELLI
Czech J. Food Sci., 2015, 33(5):405-409 | DOI: 10.17221/622/2014-CJFS
The "Breme" onion is a red-skinned cultivar growing in the northwest Italy. To date, its nutrient composition has not been described. In this study, we quantified the contents of quercetin (Q) and its glycosides and we studied their stability in the dependence on the local home-storage methods storage at 4°C and freezing. Quercetin-3,4'-O-diglycoside (3,4'-Qdg) was the most abundant form, followed by quercetin-4'-O-diglycoside (4'-Qmg ) and Q. We observed the reduction in the contents of all the analysed flavonols after storage at 4°C and after storage in frozen state. No changes have been observed in the ratio Q/3,4'-Qdg + 4'-Qmg,...
Food safety and label claims for hazelnut allergy traces: evaluation of two PCR assaysFood Chemistry and Safety
Dimitra P. HOUHOULA, Kassiani LAGOU, Maria VARVARESOU, Maria GIANNAKOUROU, Sotirios M. BRATAKOS, Vladimiros LOUGOVOIS, John TSAKNIS, Stamatis KOUSSISSIS
Czech J. Food Sci., 2015, 33(5):410-415 | DOI: 10.17221/602/2014-CJFS
The molecular techniques (C-PCR, RT-PCR) in the detection and quantification of allergic substances of hazelnut in various categories of food commodities, e.g. breakfast cereals, chocolates and biscuits, frequently involved in allergic outbreaks was implemented. For the detection of hazelnut a gene coding the major allergenic protein Cor a1 was selected. In some instances, the presence of hazelnuts is not declared on the label and the products may carry no warning for potentially allergenic substances, usually referred to as "traces". A total of 150 samples were collected from local supermarkets and analysed for the purpose of the study. From these,...
Prooxidant capacity of thermoxidised plant oilsFood Chemistry and Safety
Zuzana RÉBLOVÁ, Šárka SOUČKOVÁ, Jakub FIŠNAR, Richard KOPLÍK
Czech J. Food Sci., 2015, 33(5):416-423 | DOI: 10.17221/578/2014-CJFS
The prooxidant capacity of rapeseed, sunflower, soybean, and olive oil was determined before and after heating at a temperature of 180°C for 2, 4, and 6 hours. It was quantified as losses of α-tocopherol caused by the studied oils during 24-h incubation of their acetone-methanol solutions with addition of α-tocopherol at 30°C, whereas the decrease in α-tocopherol concentration was studied as a decrease in antioxidant capacity determined by the spectrophotometric DPPH (2,2-diphenyl-1-picrylhydrazyl) method. During heating of all the studied plant oils, the prooxidant capacity grew due to the formation of reactive lipid oxidation products,...
Content of phytosterols in raw and roasted buckwheat groats and by-productsFood Analysis, Food Quality and Nutrition
Krzysztof DZIEDZIC, Danuta GÓRECKA, Aurelie MARQUES, Magdalena RUDZIŃSKA, Grażyna PODOLSKA
Czech J. Food Sci., 2015, 33(5):424-430 | DOI: 10.17221/121/2015-CJFS
We determined the content of phytosterols in buckwheat products. Additionally, the influence of technological processing applied during buckwheat groats production on the content of some phytosterols was investigated. The highest level of phytosterols was observed in lipids extracted from roasted buckwheat hulls and raw buckwheat hulls (51.7 mg/g of lipids and 40.9 mg/g of lipids, respectively). Sitosterol and campesterol were found in the largest quantities in each sample. Technological process affected the total content of phytosterols. An increase of phytosterol content in buckwheat grains (by 107.5%) was observed, while a reduction in phytosterol...
Increasing the omega-3 content of traditional meat products by the addition of an underutilised by-product from fish processingFood Analysis, Food Quality and Nutrition
Sabine SAMPELS, Tomáš ZAJÍC, Jan MRÁZ
Czech J. Food Sci., 2015, 33(5):431-440 | DOI: 10.17221/35/2015-CJFS
The aim of our study was to find a way to use the minced fish flesh that is separated from the bones of carp after filleting (fish separate). In collaboration with the industry traditional recipes for barbecue sausages, hotdog and Vienna type sausages and liver pâté were modified by replacing a part of the meat with the fish separate. The proportion of nutritionally valuable n-3 fatty acids - eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) calculated together was 74, 54, 109, and 77 mg/100 g product in the barbecue sausage, hot dog, Vienna sausage and pâté, respectively. This means 29.6, 21.6, 43.6, and 30.8% of the daily recommended intake...
Discrimination of storage periods for Macrocybe gigantea (Massee) using UV spectral fingerprintsFood Analysis, Food Quality and Nutrition
Yan LI, Ji ZHANG, Hong-Gao LIU, Hang JIN, Yuan-Zhong WANG, Tao LI
Czech J. Food Sci., 2015, 33(5):441-448 | DOI: 10.17221/316/2014-CJFS
Macrocybe gigantea (Massee) Pegler & Lodge is a species of edible mushrooms which has important nutritional, medicinal, and economic values. Discrimination of M. gigantea with different storage periods is helpful to guarantee the authenticity and to promote marketing of this species. We focused on the establishment of the fingerprints based on UV spectroscopy to discriminate the wild-grown M. gigantea samples stored for different years and to distinguish the wild-grown and cultured samples which were stored for the same years. The analyses of the data were performed by multivariate analyses such as principal component...
Production and characterisation of alcohol-insoluble dietary fibre as a potential sourcefor functional carbohydrates produced by enzymatic depolymerisation of buckwheat hullsFood Technology and Economy, Engineering and Physical Properties
Hee Jin IM, Kyung Young YOON
Czech J. Food Sci., 2015, 33(5):449-457 | DOI: 10.17221/200/2015-CJFS
We examined the potential use of buckwheat hulls as a raw material for producing soluble dietary fibre. The insoluble fibre fraction obtained from buckwheat hulls was hydrolysed by two commercial enzymes (Celluclast 1.5L for the cellulose fraction and Viscozyme L for the hemicellulose fraction) to obtain soluble fibre hydrolysates. Alcohol-insoluble dietary fibre (AIF) was separated from the freeze-dried soluble hydrolysate by treatment with 85% ethanol. The water-holding, oil-binding, and swelling capacities of AIF were increased by enzymatic hydrolysis. AIF had significantly (P < 0.05) higher functional properties than the control. AIF...
Application of lactic acid bacteria for production of fermented beverages based on rice flourFood Technology and Economy, Engineering and Physical Properties
Michal MAGALA, Zlatica KOHAJDOVÁ, Jolana KAROVIČOVÁ, Mária GREIFOVÁ, Jarmila HOJEROVÁ
Czech J. Food Sci., 2015, 33(5):458-463 | DOI: 10.17221/74/2015-CJFS
We investigated the suitability of rice flour for fermented beverage production using various strains of lactic acid bacteria. Fermentation led to a decrease in pH from 5.04-5.17 to 3.74-4.35. At the same time, total acidity increased (1.28-2.59 g/l) due to lactic acid (0.59-2.76 g/l) and acetic acid (0.11-0.30 g/l) production. Fermentation of rice beverages also caused a gradual decrease in glucose and fructose concentration. Lactic acid bacteria proliferated in the first phases of fermentation, and cell counts reached a maximum after 12 h. The highest growth rate (vLAB = 0.44 Log10 CFU/ml/h) was observed in a sample...
Effect of extrusion treatment on the thermal stability and structure of corn starch with different emulsifiersFood Technology and Economy, Engineering and Physical Properties
Qingyu YANG, Zhigang XIAO, Yan ZHAO, Chunjing LIU, Yan XU, Junkun BAI
Czech J. Food Sci., 2015, 33(5):464-473 | DOI: 10.17221/125/2015-CJFS
Corn starch was treated with raw moisture (30%), screw speed (160 rpm), extrusion temperature (30, 55, 80, 105, 130, and 155°C), and emulsifier (1.2%) to produce the starch extrudate particles in a twin screw extruder. The influence of extrusion processing and composition (starch and emulsifier content) on the viscosity, microstructure, solubility, swelling power, and thermal stability of starch extrudate particles was examined. The SEM results showed that the surface of starch extrudate particles was quite irregular and a fissure could be clearly observed. The X-ray intensities and relative crystallinity were decreased after extrusion treatment. The...
Modification of structural and functional properties of sunflower 11S globulin hydrolysatesFood Technology and Economy, Engineering and Physical Properties
Jian Ren, Chun-Li Song, Ping Wang, Shuang Li, Narasimha-Kumar Kopparapu, Xi-Qun Zheng
Czech J. Food Sci., 2015, 33(5):474-479 | DOI: 10.17221/154/2015-CJFS
The structural and functional properties such as solubility, emulsifying properties, foaming properties, oil binding capacity, and surface hydrophobicity of sunflower 11S globulin hydrolysates generated by Alcalase at hydrolysis time of 30, 60, 90, and 120 min were evaluated. Circular dichroism analysis showed the hydrolysates possessed a decreased α-helix and β-structure. The hydrolysates exhibited lower surface hydrophobicity. Hydrolysates with shorter hydrolysis time showed the higher emulsifying activity index, but the same emulsion stability and oil binding capacity compared to the original 11S globulin. The longer hydrolysis resulted...
Hydraulic characteristic of collagenFood Technology and Economy, Engineering and Physical Properties
Rudolf ŽITNÝ, Aleš LANDFELD, Jan SKOČILAS, Jaromír ŠTANCL, Vlastimil FLEGL, Milena ZACHARIÁŠOVÁ, Monika JÍRŮ, Milan HOUŠKA
Czech J. Food Sci., 2015, 33(5):479-485 | DOI: 10.17221/62/2015-CJFS
Hydraulic characteristic of collagen. Czech J. Food Sci., 33: 479-485. The hysteresis of a hydraulic characteristic while pumping an aqueous solution of collagen through a pipe at gradually increasing and decreasing flow rates (hysteresis means that the pressure drop curve during increased flow rate is above the pressure drop during decreasing flow rate) was observed. The problem was initiated by industry and by demand for an on-line recording of rheological properties of collagenous material used for extrusion of collagen casings. The Herschel-Bulkley rheological model was capable to describe rheograms in a wide range of deformation rates; however...