Template-Type: ReDIF-Article 1.0 Author-Name: K. Melzoch Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: J. Votruba Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: B. Sekavová Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: L. Piterková Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: M. Rychtera Author-Workplace-Name: Department of Fermentation Chemistry and Bioengineering, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Thermophilic bacteria colony growth and its consequences in the food industry Abstract: The growth kinetics of thermophilic bacteria Bacillus acidocaldarius (CCM 3497), Bacillus stearothermophilus (CCMI 237), Thermus aquaticus (CCM 3488), Thermus ruber (CCM 4212), and Thermus species (CCM 4199) on solid media were studied in the temperature range of 40-60°C. The behaviour of bacterial colonies on agar plates was recorded with a digital camera during 160 hours of experiment. The growth of colony diameter was found to be linear with time at lower temperatures and an acceleration of the growth with time at suboptimal growth temperature 60°C was observed. A simple mathematical model describing the effect of irregular colony growth pattern on its rim can elucidate this unusual phenomenon. Keywords: thermophilic bacteria, colony growth, predictive modelling, microbial food spoilage Journal: Czech Journal of Food Sciences Pages: 1-8 Volume: 22 Issue: 1 Year: 2004 DOI: 10.17221/3400-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3400-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200401-0001.txt Handle: RePEc:caa:jnlcjf:v:22:y:2004:i:1:id:3400-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: H. Čížková Author-Workplace-Name: H ČÍŽKOVÁ, M VOLDŘICH, V PROKORÁTOVÁ and F KVASNIČKA Author-Name: M. Voldřich Author-Workplace-Name: H ČÍŽKOVÁ, M VOLDŘICH, V PROKORÁTOVÁ and F KVASNIČKA Author-Name: V. Prokorátová Author-Workplace-Name: H ČÍŽKOVÁ, M VOLDŘICH, V PROKORÁTOVÁ and F KVASNIČKA Author-Name: F. Kvasnička Author-Workplace-Name: H ČÍŽKOVÁ, M VOLDŘICH, V PROKORÁTOVÁ and F KVASNIČKA Title: Determination of egg yolk content in egg liqueurs Abstract: The recent Czech Food law (Decree No. 264/2003, 93/2000 and 57/2003 of the law No. 110/1997 as amended) requires the minimal concentration of egg or egg yolk content in relevant food products (mayonnaises, egg pastas, egg liqueurs), however, the methods for the determination of egg and/or egg yolk content are not sufficiently specified. The presented study deals with the development and evaluation of the analytical methods for the determination of egg yolk content in egg liqueurs. Due to the high variability of the egg composition and a possible effect of processing on the composition of the product, several chemical markers were taken into the consideration: dry matter, phosphorus, fat, cholesterol, fatty acids, and lysozyme concentrations. The egg yolk content was estimated by means of multiple regression analyses of the calibration set (model samples) and the data obtained for raw materials and described in literature. According to the egg yolk content determined, only 6 from 10 analysed samples of egg liqueurs obtained from the local market met the limit of 140 g/l (calculated with the 10% standard deviation error of estimation) required by the recent Czech legislation. Keywords: egg yolk, estimation of egg content, egg liqueur, adulteration, authenticity Journal: Czech Journal of Food Sciences Pages: 9-15 Volume: 22 Issue: 1 Year: 2004 DOI: 10.17221/3401-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3401-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200401-0002.txt Handle: RePEc:caa:jnlcjf:v:22:y:2004:i:1:id:3401-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: I. Švec Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: M. Hrušková Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Wheat flour fermentation study Abstract: Fermentograph and baking properties of 98 wheat flour samples (two sets of commercial and one set of variety) were evaluated in the form of fermented dough. Analytical traits (ash and protein contents, wet gluten, Falling Number, Zeleny sedimentation value), fermentograph parameters (gases volume, the volume of dough and the time of its max. increase), and the laboratory baking test were used for the characterisation of flours and doughs. Differences found between the two commercial flour sets were small and were influenced by the year of harvest. Significant differences were found between commercial and variety flours both in the fermentograph behaviour and in the baking test results. Lower dough volumes and lower bread specific volumes for variety flours in comparison with commercial ones were caused by a worse quality of proteins. Statistical analysis on significance level 99% showed correlations between the gases volume and the dough volume r = 0.5264), between the gases volume and the time of dough maximum (r = -0.7689), and between the dough volume and the specific volume of bread (r = 0.5452). Keywords: wheat flour, fermented dough, fermentograph, baking test, maturograph, oven rice recorder Journal: Czech Journal of Food Sciences Pages: 17-23 Volume: 22 Issue: 1 Year: 2004 DOI: 10.17221/3402-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3402-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200401-0003.txt Handle: RePEc:caa:jnlcjf:v:22:y:2004:i:1:id:3402-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Poustka Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: J. Hajšlová Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: K. Holadová Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Author-Name: K. Nováková Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology in Prague, Prague, Czech Republic Title: Potential of liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry for determination of fosetyl-aluminium residues in dried hops Abstract: New analytical procedure for the determination of fosetyl-aluminium in hop cones (also called "hops") was developed. Liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry (LC-APCI-MS/MS) allowed a highly selective determination of this fungicide which facilitated the sample preparation. The sufficiently low detection limit (1 mg/kg of dried hops) with the acceptable method performance characteristics (RSD 9%, recovery 76% - at the level of 10 mg/kg) complies with the need to inspect the observance of maximal residual limit 100 mg/kg. The application of LC-MS technique thus provided an effective way of fosetyl-aluminium determination in the complex hops matrix. Keywords: fosetyl-aluminium, pesticide residues, hops analysis, liquid chromatography, mass spectrometry Journal: Czech Journal of Food Sciences Pages: 24-28 Volume: 22 Issue: 1 Year: 2004 DOI: 10.17221/3403-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3403-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200401-0004.txt Handle: RePEc:caa:jnlcjf:v:22:y:2004:i:1:id:3403-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: O. Lapčík Author-Workplace-Name: O LAPČÍK Title: Endocrinological aspects of dietary habits Abstract: Dietary habits reflect both the recent economic possibilities and the cultural history of individual human populations. They may influence endocrine systems and thus affect the health of the respective populations in several manners: (1) People consuming exclusively local products may lack certain micronutrients. This is important especially in areas with low levels of iodine and/or selenium in the environment. Thyroid gland insufficiency resulting from the iodine deficiency was widespread in many areas of Central Europe until the introduction of iodine supplementation in the second half of 20th century. Iodine deficiency is still a serious problem in many areas of Africa and Asia. (2) Numerous cultural plants contain compounds able to influence important metabolic pathways. Iodine deficiency is usually worsened by thyroidal peroxidase inhibitors, so-called goitrogens. Phenolic and terpenoid compounds may interfere in the metabolism of steroid hormones. Glycyrrhetinic acid from licorice is a potent inhibitor of 11-beta-hydroxysteroid dehydrogenase. Isoflavonoids from legumes (e.g. genistein and daidzein) and their metabolites (e.g. equol) were found to inhibit the following enzymes: aromatase, 5alfa-reductase, 7alfa-hydroxylase, 3beta-hydroxysteroid and 17beta-hydroxysteroid dehydrogenases, etc. Isoflavonoid sulphates influence local availability of steroids by inhibiting sterol sulphatases. (3) Plant-derived compounds are able to interact with nuclear receptors and act either as hormone agonists or as antagonists. Recently, the attention has been paid namely to the phenolic substances interacting with oestrogen receptors so-called phyto-oestrogens. Keywords: dietary habits, thyroid gland, endemic thyreopathie, goitrogen, steroid, mineralcorticoid, phyto-oestrogen, inhibitor, enzym, receptor Journal: Czech Journal of Food Sciences Pages: 29-38 Volume: 22 Issue: 1 Year: 2004 DOI: 10.17221/3404-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3404-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200401-0005.txt Handle: RePEc:caa:jnlcjf:v:22:y:2004:i:1:id:3404-CJFS