Czech Journal of Food Sciences, 2011 (vol. 29), issue 5
Design of a method to evaluate yeasts to be used as starter cultures in dry-cured meat products
Eva M. Casado, Juan J. Córdoba, María J. Andrade, Mar Rodríguez
Czech J. Food Sci., 2011, 29(5):463-470 | DOI: 10.17221/41/2010-CJFS 
Some yeasts are involved in flavour development of dry-cured meat products showing a positive impact on the generation of volatile compounds. The aim of this work was to design a method of routine analysis to evaluate the production of volatile compounds by yeasts to be selected as starter cultures. For this purpose, several variations of a minimum culture medium that included free amino acids, oleic acid, and α-ketoglutarate, incubated under similar conditions of water activity and pH as dry-cured meat products, were assayed. In these conditions, the representative yeast strains isolated from a dry-cured meat product were tested. The volatile...
Comparison of the results of the ELISA, histochemical, and immunohistochemical detection of soya proteins in meat products
Matej Pospiech, Bohuslava Tremlová, Eva Renčová, Zdeňka Randulová, Zuzana Řezáčová Lukášková, Jana Pokorná
Czech J. Food Sci., 2011, 29(5):471-479 | DOI: 10.17221/209/2010-CJFS
This work compares the commonly used immunochemical methods for soya protein detection and alternative microscopic methods. Immunochemical methods were represented by the competitive ELISA method. Histochemical and immunohistochemical methods were used for microscopical examination. From a group of 252 meat products, each sample was examined for soya proteins by ELISA, histochemical, and immunohistochemical methods. The products came from the following categories: cooked sausages, ham, dry cooked sausages, and fermented sausages. The results showed that the highest accuracy was achieved by immunohistochemical examination. However, in the category of...
Compositional characteristics and nutritional quality of Eurasian beaver (Castor fiber) meat
V. Razmaité, R. Šveistiené, G.J. Švirmickas
Czech J. Food Sci., 2011, 29(5):480-486 | DOI: 10.17221/313/2010-CJFS
The meat of Eurasian beaver (Castor fiber) as obtained in Lithuania contained 21.4% crude protein with high amounts of glutamic acid (152.6 mg/g), aspartic acid (87.6 mg/g), lysine (81.8 mg/g), leucine (75.7 mg/g), arginine (60.4 mg/g), and isoleucine (60.1 mg/g). This meat could be a high quality protein source because of its well-balanced essential amino acid composition. Polyunsaturated fatty acids were predominant with a percentage of 41.58% in thighs and of 42.12% in the fat depot of tails. Hexadecanoic acid (C16:0) was the dominant fatty acid in thigh muscles, followed by octadecadienoic (C18:2n-6), octadecenoic (C18:1), and octadecatrienoic...
A new look at the assessment of the silver carp (Hypophthalmichthys molitrix Val.) as a food fish ;
Hana Buchtová, František Ježek
Czech J. Food Sci., 2011, 29(5):487-497 | DOI: 10.17221/392/2010-CJFS
The principal aim was to analyse the chemical composition (dry matter, protein, fat, saccharides, ash) and to calculate the energy value of 6 topographically distinct parts (cranial, medial and caudal dorsal/ventral part above/below the lateral line) of the fillets of the silver carp (Hypophthalmichthys molitrix Val.) in two weight categories, i.e. lightweight (LW) fish of 3.50 kg live weight, and heavyweight (HW) fish of 4.50 kg live weight. Another aim was to evaluate the lipid profile of the muscle tissue and internal fat (separated from the internal organs). The study demonstrated differences (P < 0.05) in the chemical composition...
Novel approaches to determination of PAHs and halogenated POPs in canned fish
Lucie Drábová, Jana Pulkrabová, Kamila Kalachová, Jaromír Hradecký, Marie Suchanová, Monika Tomaniová, Vladimír Kocourek, Jana Hajšlová
Czech J. Food Sci., 2011, 29(5):498-507 | DOI: 10.17221/405/2010-CJFS
A simple method is described for simultaneous isolation of 7 indicator polychlorinated biphenyls (PCBs), 10 polybrominated diphenyl ethers (PBDEs), 22 organochlorine pesticides (OCPs), and 16 polycyclic aromatic hydrocarbons (16 EU PAHs). The sample preparation procedure, including a pressurised liquid extraction (PLE) followed by gel permeation chromatography (GPC) for the selective isolation of the target compounds, was optimised and validated. For the final identification/quantitation of the target PCBs, PBDEs, OCPs, and PAHs, gas chromatography (GC) coupled to a high speed time-of-flight mass spectrometer (TOF MS) was used. The performance characteristics...
Effect of power ultrasound on the immunoactivity and texture changes of shrimp (Penaeus vannamei)
Xiaoyan Li, Zhenxing Li, Hong Lin, Haider Samee
Czech J. Food Sci., 2011, 29(5):508-514 | DOI: 10.17221/242/2009-CJFS
The aim of this study was to examine the effect of power ultrasound on the allergenicity and texture properties of shrimp (Penaeus vannamei). For this purpose, raw and boiled shrimps were treated with power ultrasound (30 kHz, 800 W) at 0°C and 50°C for 0, 2, 8, 10, and 30 minutes. The results showed that the ultrasound treatment had a greater effect on the allergenicity of the boiled shrimps than of the raw ones, while with hardness it was vice versa. The allergenicity of the boiled shrimps treated at 0°C (treatment 3) and 50°C (treatment 4) decreased by nearly 50% and 40%, respectively, with 10 min of the treatment duration. As...
Specific rotation and carbohydrate profile of Croatian unifloral honeys
Ljiljana Primorac, Ivana Flanjak, Daniela Kenjerić, Dragan Bubalo, Zoran Topolnjak
Czech J. Food Sci., 2011, 29(5):515-519 | DOI: 10.17221/164/2010-CJFS
Specific rotation and carbohydrate profile of Croatian black locust (Robinia pseudoacacia L.), sage (Salvia officinalis L.) and chestnut (Castanea sativa Mill.) honeys were determined. Fructose, glucose, sucrose, maltose (with cellobiose and trehalose), melezitose (with erlose), raffinose, and xylose were evaluated and quantified by HPLC, while specific rotation was determined by using a polarimeter. The differences in the carbohydrate profile, especially in disaccharide and trisaccharide contents, reflected different specific rotation values of the honey types selected. Weak positive correlations between specific rotation...
Extruded corn flour changed the functionality behaviour of blends
Jie Zeng, Haiyan Gao, Guanglei Li, Xinhong Liang
Czech J. Food Sci., 2011, 29(5):520-527 | DOI: 10.17221/13/2010-CJFS
Functionalities and relationships between raw and extruded maize flour blends were studied. The extruded flour had higher water absorption and water solubility indices, and had no differential scanning calorimetry endotherm. The parameters of RVA peak, breakdown, setback, and final viscosity were lowered and the parameters of cold viscosity were improved as the fraction of the extruded flour in the mixture increased. In starches from raw flour, a bimodal distribution of the chain length was found by gel permeation chromatography while in the extruded starches only one fraction was observed. The dough quality of 60% raw and 40% extruded flour mixture...
Modelling the carrot thin-layer drying in a semi-industrial continuous band dryer
Mortaza Aghbashlo, Mohammad Hossien Kianmehr, Akbar Arabhosseini, Tayyeb Nazghelichi
Czech J. Food Sci., 2011, 29(5):528-538 | DOI: 10.17221/158/2010-CJFS
This paper presents a mathematical modelling of the drying process in a semi-industrial continuous band dryer. Carrot slices with the thickness of 5 mm were used for the drying experiments. The experiments were conducted at three air temperatures, 50, 60, and 70°C, three air velocities, 0.5, 1.0, and 1.5 m/s, and three chain linear velocities, 2.38 × 10-4, 2.78 × 10-4, and 3.33 × 10-4 m/s with three replications for each treatment. The Lewis, Henderson & Pabis, and Page models were fitted to the experimental data of the moisture ratio against the sample position using non-linear regression analysis by MATLAB computer...
Influence of chemical composition and environmental conditions on the textural properties of dried fruit bars
Sibel Ozilgen
Czech J. Food Sci., 2011, 29(5):539-547 | DOI: 10.17221/303/2009-CJFS
The influences of the composition, environmental humidity, and temperature on the stability of dried fruit bars during storage were investigated. Sultana bars were chosen to represent similar types of fruit bars. The moisture sorption isotherms and textural stability of sultana bars with and without glucose and maltodextrin additives were determined at 20°C and 40°C using the standard static gravimetric method. The shape of all of the isotherms was found to be typical of high sugar foods and could be explained by four different models. Additives and storage temperatures affected the monolayer moisture content, equilibrium moisture content, and the...
Contents of sulforaphane and total isothiocyanates, antimutagenic activity, and inhibition of clastogenicity in pulp
Jiří Totušek, Jan Tříska, Danuše Lefnerová, Jan Strohalm, Naděžda Vrchotová, Ondřej Zendulka, Jiřina Průchová, Jana Chaloupková, Pavla Novotná, Milan Houška
Czech J. Food Sci., 2011, 29(5):548-556 | DOI: 10.17221/394/2010-CJFS
The consumption of Cruciferous vegetables is important for the prevention of cancerous diseases, particularly colorectal cancer. The effects of technological treatments (freezing, pasteurisation, high-pressure treatment) on the content of isothiocyanates, considered to be the active substance, were observed in single-species vegetable juices prepared from cruciferous vegetables (broccoli, cauliflower, Brussels sprouts, white and red cabbage). The contents of sulforaphane and total isothiocyanates were studied relative to the temperature, action period, and time delay after juice pressing. Sulforaphane and total isothiocyanates were determined...
Optimisation of solid-state fermentation of Aspergillus niger JL-15 for xylanase production and xylooligosaccharides preparation
Xian-Jun Dai, Ming-Qi Liu, Hong-Xiao Jin, Ming-Yan Jing
Czech J. Food Sci., 2011, 29(5):557-567 | DOI: 10.17221/103/2010-CJFS
The production of xylanase (XylA) by Aspergillus niger JL-15 in solid-state fermentation (SSF) on orange peel was optimised by the response surface methodology (RSM). The results revealed that four factors had significant effects on the XylA production (P < 0.05), that is the concentrations of the added glycerin and ammonium sulfate, the moisture content, and fermentation time. Exploying orange peel as the solid substrate, maximum xylanase activity (917.7 U/g dry fermentation product) was obtained at 4.2% glycerin, 3.1% (NH4)2SO4, 61% moisture content, and 73.4-h fermentation, this activity being...