Template-Type: ReDIF-Article 1.0 Author-Name: Jan Velíšek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Author-Name: Karel Cejpek Author-Workplace-Name: Department of Food Chemistry and Analysis, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Title: Biosynthesis of food constituents: Saccharides. 2. Polysaccharides - a review Abstract: This review article gives a survey of the selected principal biosynthetic pathways that lead to the most important polysaccharides occurring in foods and in food raw materials and informs non-specialist readers about new scientific advances as reported in recently published papers. Subdivision of the topic is predominantly done via biosynthesis and includes reserve polysaccharides (starch and glycogen, fructans), plant cell wall polysaccharides (cellulose and callose, pectin), and animal polysaccharides (chitin and glycosaminoglycans). Extensively used are the reaction schemes, sequences, and mechanisms with the enzymes involved and detailed explanations using sound chemical principles and mechanisms. Keywords: biosynthesis, polysaccharides, starch, glycogen, fructans, cellulose, callose, pectin, chitin, glycosylaminoglycans, mucopolysaccharides Journal: Czech Journal of Food Sciences Pages: 173-183 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3388-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3388-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0001.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3388-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ondřej Jirsa Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Author-Name: Marie Hrušková Author-Workplace-Name: Department of Carbohydrate Chemistry and Technology, Faculty of Food and Biochemical Technology, Institute of Chemical Technology Prague, Prague, Czech Republic Title: Characteristics of fermented dough predicted by using the NIR technique Abstract: Rheological characteristics of wheat doughs prepared from 179 variety and commercial wheat flour samples (crop years 1999, 2001, 2002, 2003 and 2004) were assessed with SJA fermentograph (Sweden). NIR spectra of the samples were measured on the spectrometer NIRSystem 6500. Calibration equations with cross and independent validations for all rheological characteristics were computed by NIR Software ISI Present WINISI II using mPLS/PLS regression and ANN. The quality of prediction was evaluated by means of coefficients of correlation between the measured and the predicted values from cross and independent validation. A statistically significant dependence (with probability higher than 99%) was determined in all mentioned rheological characteristics in the case of cross-validation. The results suggested the possibility of prediction particularly for the fermentation gas volume parameter, where a high correlation was achieved (r = 0.888). The accuracy of prediction by independent validation was not found on such a satisfactory level. For the sets of ten commercial flours, higher correlation coefficient was calculated for the final dough volume parameter. Keywords: wheat flour dough, fermentograph, NIRSystem 6500, prediction of rheological characteristics Journal: Czech Journal of Food Sciences Pages: 184-189 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3389-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3389-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0002.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3389-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Ilyas Çelik Author-Workplace-Name: Food Engineering Department, Engineering Faculty, Pamukkale University, Camlik, Denizli, Turkey Author-Name: Fatma ISIK Author-Workplace-Name: Food Engineering Department, Engineering Faculty, Pamukkale University, Camlik, Denizli, Turkey Author-Name: Omer Simsek Author-Workplace-Name: Food Engineering Department, Engineering Faculty, Pamukkale University, Camlik, Denizli, Turkey Author-Name: Oguz Gursoy Author-Workplace-Name: Food Engineering Department, Engineering Faculty, Pamukkale University, Camlik, Denizli, Turkey Author-Workplace-Name: Department of Dairy Technology, Faculty of Agriculture, Ege University, Bornova, Izmir, Turkey Title: The effects of the addition of baker's yeast on the functional properties and quality of tarhana, a traditional fermented food Abstract: As a fermented product, tarhana is the dry form of yogurt-cereal mixture and represents an important part of the diets of many people in different countries including Turkey. In the present study, the effects of the addition of baker's yeast on the quality and functional properties of tarhana were investigated. Tarhana was produced under laboratory conditions (uncontrolled and controlled conditions) using two formulas. Some physicochemical, functional, and sensory properties of the samples were analysed. An increase was found in the acidity value of all samples during the fermentation period. The addition of baker's yeast affected the functional properties (water absorption capacity, foaming capacity, foaming stability, emulsifying activity) of the samples (P< 0.05). The tarhana samples produced by the addition of yeast and under controlled conditions had shorter fermentation times and better sensory properties. This research suggests that the addition of baker's yeast and the employment of controlled conditions can be recommended in the production of the commercial type of tarhana. Keywords: soup, fermentation, tarhana, yeast, flour Journal: Czech Journal of Food Sciences Pages: 190-195 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3390-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3390-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0003.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3390-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Marie Holasová Author-Workplace-Name: Department of Nutritive Substances, Food Research Institute Prague, Prague, Czech Republic Author-Name: Vlasta Fiedlerová Author-Workplace-Name: Department of Nutritive Substances, Food Research Institute Prague, Prague, Czech Republic Author-Name: Petr Roubal Author-Workplace-Name: Dairy Research Institute, MILCOM, Corp., Prague, Czech Republic Author-Name: Martina Pechačová Author-Workplace-Name: Dairy Research Institute, MILCOM, Corp., Prague, Czech Republic Title: Possibility of increasing natural folate content in fermented milk products by fermentation and fruit component addition Abstract: The possibility of the increase of the natural folate content in fermented milk products by the fermentation process and by the addition of fruit component was evaluated. 5-methyltetrahydrofolate (5-MTHF) content was followed after the inoculation of pasteurised milk with the butter starter and the selected strains of Streptococcus thermophilus in combination with Bifidobacterium longum or Propionibacterium freudenreichii subsp. shermanii followed by fermentation at 30°C and 37°C for 12 and 18 h. 5-MTHF was determined by HPLC method after deconjugation with hog kidney conjugase and SPE SAX purification. The highest 5-MTHF content increase of 4.03 ± 0.44 µg/100 g was found at cofermentation with Streptococcus thermophilus No. 144 and Propionibacterium freudenreichii subsp. shermanii No. 160 at 37°C after 12 h of fermentation. 9 commercial fruit components used in dairy industry contained between 0.17-9.11 µg 5-MTHF/100 g. The components produced with pineapple, sour cherry, apricot, and apple contained low amounts of 5-MTHF - less than 1 µg/100 g. Among the rest of the components tested, the strawberry component proved to be the best source of folate with the content of 9.11 µg 5-MTHF/100 g. The values in 7 varieties of fresh fully ripe strawberries fluctuated between 25.5 and 54.0 µg/100 g fresh sample, i.e. 272 and 554 µg/100 g dry matter with the highest content found in the varieties Elsanta and Honeyoe. Fully ripe berries of the variety Senga Sengana contained by 63% more 5-MTHF in comparison with unripe berries. In order to reach maximum folate content in the fruit component, fully ripe strawberries of the cultivars Elsanta and Honeyoe are recommended for the processing. The folate content in the fermented milk product may be increased in this way by 4.8 µg/100 g, with 69% originating from the fermentation and 31% from the fruit component addition. Keywords: folate, fermentation, fruit, fermented milk products Journal: Czech Journal of Food Sciences Pages: 196-201 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3391-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3391-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0004.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3391-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Martina Langová Author-Workplace-Name: Department of General Biology and Genetics, Center of Biomedical Science and Author-Name: Zdeňka Polívková Author-Workplace-Name: Department of General Biology and Genetics, Center of Biomedical Science and Author-Name: Petr Šmerák Author-Workplace-Name: Department of General Biology and Genetics, Center of Biomedical Science and Author-Name: Jiřina Bártová Author-Workplace-Name: Department of General Hygiene, Center of Preventive Medicine, 3 rd Faculty of Medicine, Charles University, Prague, Czech Republic Author-Name: Ivo Bárta Author-Workplace-Name: Department of General Biology and Genetics, Center of Biomedical Science and Title: Antimutagenic effect of resveratrol Abstract: Evidence exists from population-based and laboratory studies that some phytochemicals have protective effects against tumors or other diseases and reveal antimutagenic activity. We studied the protective effect of the plant phytoallexin resveratrol on the mutagenic activity of three mutagens, i.e. aflatoxin B1 (AFB1), 2-amino-3-methylimidazo[4,5-f]qui-noline (IQ) and N-nitroso-N-methylurea (MNU) using the Ames and the micronucleus tests. In the Ames test, we proved a significant antimutagenic activity only against the indirect mutagens AFB1 and IQ, not against the direct mutagen MNU. A significant decrease of mutagenicity of all three mutagens was detected by the micronucleus test. Keywords: resveratrol, aflatoxin B1, 2-amino-3-methylimidazo[4, 5-f]quinoline, N-nitroso-N-methylurea Journal: Czech Journal of Food Sciences Pages: 202-208 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3392-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3392-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0005.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3392-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: Tomáš Komprda Author-Workplace-Name: Department of Food Technology, Faculty of Agronomy, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic Author-Name: Kateřina Novická Author-Workplace-Name: Department of Food Technology, Faculty of Agronomy, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic Author-Name: Libor Kalhotka Author-Workplace-Name: Department of Food Technology, Faculty of Agronomy, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic Author-Name: Dana Smělá Author-Workplace-Name: Czech Agriculture and Food Inspection Authority, Brno, Czech Republic Title: Biogenic amine content in sterilised and pasteurised long-term stored processed cheese Abstract: The contents of eight biogenic amines (tryptamine, phenylethylamine, histamine, tyramine, putrescine, cadaverine, spermidine and spermine) were determined in samples of processed cheese, either pasteurised (P) or sterilised (S), and consequently stored for either 22 or 57 weeks at the temperatures of 8°C and 22°C, respectively. Tyramine was quantitatively the most important biogenic amine (1.3-29.3 mg/kg); the highest level (P < 0.05) was found in P cheese stored for 22 weeks after processing at 8°C (P1). Regardless of tyramine, and with the exception of putrescine in S cheese stored for 57 weeks (2.2 mg/kg), the content of no biogenic amine exceeded 2 mg/kgin any tested sample. Significantly higher (by five to six orders of magnitude; P < 0.05) counts of total aerobic and facultative anaerobic microorganisms in P1 sample in comparison with all other samples were indicative of the cover leakage. No lactic acid bacteria were detected in any sample, the counts of coliforms and total anaerobes, respectively, were negligible and did not differ (P> 0.05) between samples. No sample of the tested long-term stored processed cheese was considered unsafe from the toxicological viewpoint. Keywords: tyramine, polyamines, spoilage bacteria, food safety Journal: Czech Journal of Food Sciences Pages: 209-216 Volume: 23 Issue: 5 Year: 2005 DOI: 10.17221/3393-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/3393-CJFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/cjf-200505-0006.txt Handle: RePEc:caa:jnlcjf:v:23:y:2005:i:5:id:3393-CJFS