Czech Journal of Food Sciences, 2005 (vol. 23), issue 5
Biosynthesis of food constituents: Saccharides. 2. Polysaccharides - a review
Jan Velíšek, Karel Cejpek
Czech J. Food Sci., 2005, 23(5):173-183 | DOI: 10.17221/3388-CJFS 
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...
Characteristics of fermented dough predicted by using the NIR technique
Ondřej Jirsa, Marie Hrušková
Czech J. Food Sci., 2005, 23(5):184-189 | DOI: 10.17221/3389-CJFS
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...
The effects of the addition of baker's yeast on the functional properties and quality of tarhana, a traditional fermented food
Ilyas Çelik, Fatma ISIK, Omer Simsek, Oguz Gursoy
Czech J. Food Sci., 2005, 23(5):190-195 | DOI: 10.17221/3390-CJFS
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...
Possibility of increasing natural folate content in fermented milk products by fermentation and fruit component addition
Marie Holasová, Vlasta Fiedlerová, Petr Roubal, Martina Pechačová
Czech J. Food Sci., 2005, 23(5):196-201 | DOI: 10.17221/3391-CJFS
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....
Antimutagenic effect of resveratrol
Martina Langová, Zdeňka Polívková, Petr Šmerák, Jiřina Bártová, Ivo Bárta
Czech J. Food Sci., 2005, 23(5):202-208 | DOI: 10.17221/3392-CJFS
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...
Biogenic amine content in sterilised and pasteurised long-term stored processed cheese
Tomáš Komprda, Kateřina Novická, Libor Kalhotka, Dana Smělá
Czech J. Food Sci., 2005, 23(5):209-216 | DOI: 10.17221/3393-CJFS
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...