Czech Journal of Food Sciences, 2008 (vol. 26), issue 6

Index of volume 26, Author index, Author institution index, List of reviewers, Subject indexIndex

editors

Czech J. Food Sci., 2008, 26(6):I-XIV | DOI: 10.17221/1364-CJFS  

Screening methods used for the detection of veterinary drug residues in raw cow milk - a review

Pavlína Navrátilová

Czech J. Food Sci., 2008, 26(6):393-401 | DOI: 10.17221/2438-CJFS  

At both national and international levels, increasing attention is paid to the evaluation of the risk of occurrence of veterinary drug residues in foodstuffs and foods of animal origin, and to the introduction of appropriate measures to reduce this risk. The design and strategy of antibiotics and sulphonamide detection in milk involve two different aspects: the ability to sell the milk depending on its quality (technological safety), and the health safety of the milk regulated by the recent legislative regulations (toxicological safety). Veterinary drug residues in milk represent a health risk for the consumer. This review describes the methods used...

Better bread from vigorous grain?

Oldřich Chloupek, Zdeněk Both, Vítězslav Dostál, Pavlína Hrstková, Tomáš Středa, Thomas Betsche, Marie Hrušková, Vladimíra Horáková

Czech J. Food Sci., 2008, 26(6):402-412 | DOI: 10.17221/66/2008-CJFS  

A high seed vigour is a desired trait in agronomy as it promotes the fast field emergence and homogeneity of harvest, which is necessary for producing quality food raw material. In this work, we studied the effects of the seed vigour on the bread quality. Relationships between the grain vigour, nutrients and anti-nutrients, contents, and bread volume were evaluated using the samples acquired from official variety trials. In the trials, the grain vigour was perceived as the grain ability to germinate in stress conditions, i.e. at 10°C in a solution of polyethylene glycol (PEG 6000 at osmotic pressure - 2 bars, the so called permanent wilting point)....

Sorption and thermal properties of rice, potato starch, and oat flakes

Aleš LANDFELD, Milan HOUŠKA, Karel HOKE

Czech J. Food Sci., 2008, 26(6):413-420 | DOI: 10.17221/1363-CJFS  

A precise design of the equipment for thermal sterilisation of rice, potato starch, and oat flakes by dry heat requires the knowledge of the relevant values of physical properties of these products. Water activity and enthalpy are presented as functions of temperature and humidity. Water activity was measured as a function of the moisture content and temperature in the desorption process that reproduces the real conditions existing during dry heat processing in the pilot rotating steriliser equipment. The heat of evaporation can be predicted from these data as a function of the moisture content of these products. DSC (differential scanning calorimetry)...

Colour evaluation of different pasta samples

Ivan Švec, Marie Hrušková, Michaela Vítová, Hana Sekerová

Czech J. Food Sci., 2008, 26(6):421-427 | DOI: 10.17221/83/2008-CJFS  

The colour of the laboratory prepared pasta was evaluated with respect to wheat flour types (M1 bright, M2 semi-bright, and M3 semolina), egg-ratio (0, 1, 2), and non-traditional cereals (archaic wheat species, tritordeum, spring barley, millet, lupin, buckwheat, and soya) supplements. The flour colour measurement confirmed its dependence on the wheat species milled - M3 obtained from durum wheat had a lower whiteness L* (89.6) and a higher yellowness b* (22.2) than the flour from common wheat (e.g. 93.6 and 8.1 for M1, respectively). As presumed, with the rising egg-ratio pasta yellowness increased - for M1-pasta, the calculated colour...

Contents of some biologically active amines in a Czech blue-vein cheese

Tomáš Komprda, Vlastimil Dohnal, Renata Závodníková

Czech J. Food Sci., 2008, 26(6):428-440 | DOI: 10.17221/7/2008-CJFS  

Biogenic amines (histamine, tyramine, tryptamine, phenylethylamine, cadaverine) including biologically active polyamines (putrescine, spermidine and spermine) were determined by HPLC method after 7, 21, 35, and 49 days of ripening in the core (C) and edge (E) samples of a blue-veined cheese, popular in the Czech Republic under the trade mark Niva, produced in the three consecutive months (October, November, December) from pasteurised cow milk using Penicillium roqueforti spores; two vats were produced in each month. The cheese vat, including the production period, accounted for (P < 0.05) one third and two thirds of the explained...

Mushrooms of genus Pleurotus as a source of dietary fibres and glucans for food supplements

Andriy Synytsya, Kateřina Míčková, Ivan Jablonský, Marcela SLUKOVÁ, Jana Čopíková

Czech J. Food Sci., 2008, 26(6):441-446 | DOI: 10.17221/1361-CJFS  

Fruit bodies (separately pilei and stems) of mushrooms Pleurotus ostreatus (four strains) and Pleurotus eryngii were characterised as a source of polysaccharides. The contents of glucans and dietary fibres were determined with using the respective Megazyme enzymatic kits. Enzymatic analysis of the fruit bodies confirmed significant differences in the contents of these components among the species and strains. The stems contained more insoluble dietary fibres than the pilei in all the cases and more β-glucans in most cases. However, relatively high contents of β-glucan (20-50% of dry matter) could be a result of incomplete enzymatic...

Antioxidant activity of peanut skin extracts from conventional and high-oleic peanuts

Van Ha HOANG, Petra APOŠTOLOVÁ, Jana DOSTÁLOVÁ, František PUDIL, Jan POKORNÝ

Czech J. Food Sci., 2008, 26(6):447-457 | DOI: 10.17221/29/2008-CJFS  

Peanut skins were isolated from deshelled and dried conventional and high-oleic peanuts. In order to obtain simpler mixtures of phenolics with other components of the respective extract, the samples were extracted with solvents of increasing polarity (hexane, ethyl acetate, and methanol). The amounts of extracts were as follows: methanol > hexane > ethyl acetate, and the contents of phenolic constituents in the extracts: ethyl acetate > methanol > hexane. Ethyl acetate extracts from the skins of both conventional and high-oleic peanuts were about the same. The amount of peanut skin ethyl acetate extract was higher than that of tea leaves,...

FT-IR spectroscopic characteristics of differently cultivated Escherichia coli

Zdenek FILIP, SUSANNE HERMANN, KATEŘINA DEMNEROVÁ

Czech J. Food Sci., 2008, 26(6):458-463 | DOI: 10.17221/14/2008-CJFS  

FT-IR spectra were recorded of Escherichia coli cell mass with the aim of obtaining spectral traits possibly useful in a rapid detection and characterisation of this indicator bacterium. A well differentiated spectrum was obtained from the cell mass harvested in a stationary phase of growth, e.g., after 24 h, from a minimum nutrient broth. The cell mass, harvested either earlier or grown in nutrient solutions which contained an enhanced carbon or nitrogen concentrations delivered somewhat different IR spectra, apparently due to a higher content of nucleic acid components as related to other structural constituents of bacterial cells. Consequently,...

Effect of lean meat proportion on the chemical composition of pork

Monika Okrouhlá, Roman Stupka, Jaroslav Čítek, Michal Šprysl, Milan Trnka, Eva Kluzáková

Czech J. Food Sci., 2008, 26(6):464-469 | DOI: 10.17221/18/2008-CJFS  

The objective of this work was to verify the effect of the lean meat proportion on the chemical composition of the meaty parts (loin and ham) of pork. A total of 116 finishing hybrid pigs commonly used in the Czech Republic were fattened for this purpose. The pigs were divided according to the lean meat proportion criterion into 3 groups, i.e. more than 60.0%, 55.0-59.9% and 50.0-54.9%. Representative muscle samples were taken from the right halves of these pigs. They were then homogenised and submitted to chemical analysis. The results of the measuring showed that the values of the water content, intramuscular fat (IMF), crude proteins, and ash matter...