Czech Journal of Food Sciences, 2001 (vol. 19), issue 5
Unusual behavior of natural polyphosphates during IMAC
M. Kmínková, A. Prošková, J. Kučera
Czech J. Food Sci., 2001, 19(5):161-165 | DOI: 10.17221/6601-CJFS 
The atypical course of IDA-ferric (Imino-Di-Acetyl-agarose saturated with ferric ions) of two polyphosphorylated compounds - phytic acid and Ser(P)-Ser(P)-Ser(P)-Glu-Glu cluster obtained by the way of pancreatic hydrolysis of bovine casein was detected. The spectral data (for phytic acid) and iron content (for polyphosphate cluster) indicate the strong bond of ferric ions to these polyphosphorylated compounds. The data shows these compounds to bind ferric ion stronger even in comparison with IDA (Imino-Di-Acetate) itself. Therefore attention is to be paid to all IMAC (Immobilized-Metal-Ion-Affinity-Chromatography) of natural compounds containing strong...
Effect of yeast extract supplementation on β-galactosidase activity of Lactobacillus delbrueckii subsp. bulgaricus 11842 grown in whey.
D. Bury, J. Geciova, P. Jelen
Czech J. Food Sci., 2001, 19(5):166-170 | DOI: 10.17221/6602-CJFS
Lactobacillus delbrueckii subsp. bulgaricus 11842 (LB 11842) was grown in reconstituted sweet whey supplemented with 0 to 1% yeast extract. The β-galactosidase activity was determined from the hydrolysis of o-nitrophenyl- β-D-galactopyranoside (ONPG) by sonicated cultures. Shake flask cultures containing 0.2-0.8% yeast extract gave 2.5 times higher β-galactosidase activity than LB 11842 grown in sole (intact) whey. When supplementation with 1% yeast extract resulted even in a threefold increase of β-galactosidase activity. The rate of acid production increased with the addition of yeast extract, while...
Lactococcus lactis subsp. lactis LTM 32, a new bacteriocin-producing strain isolated from Vietnamese fermented milk
T.M. DO, M. Plocková, J. Chumchalová
Czech J. Food Sci., 2001, 19(5):171-176 | DOI: 10.17221/6603-CJFS
Screening for bacteriocin production of 60 strains of lactic acid bacteria (LAB) both isolated from various Vietnamese fermented food and obtained from the culture collection resulted in the detection of a bacteriocin-producing strain, Lactococcus lactis subsp. lactis LTM 32 isolated from Vietnamese fermented milk. This strain was identified and partly characterized. This bacteriocin inhibited not only closely relative strains of LAB but also strains of Listeria monocytogenes, Bacillus sp. including B. cereus, B. stearothermophilus, B. subtilis, B. pumilus and Staphylococcus...
Fatty acids in lipids of carp (Cyprinus carpio) tissues
M. Kmínková, R. Winterová, J. Kučera
Czech J. Food Sci., 2001, 19(5):177-181 | DOI: 10.17221/6604-CJFS
The content of fat in carp (Cyprinus carpio) tissue was evaluated throughout one year. The following tissues were evaluated: skeletal muscle, soft roe, hard roe, fat tissue, and hepatopancreas. Respective fatty acids were determined using gas liquid chromatography (GLC). The highest content of valuable polyunsaturated acids, like eicosahexaenoic acid, was found in soft roe and in skeletal muscle during summer, in hepatopancreas during spring, in hard roe during fall. The content of eicosahexaenoic acid in hard roe remains high in all seasons except summer. Saturated fatty acids like palmitic acid and stearic acid do not fluctuate very much...
The cereal grains: focus on vitamin E
H. Zielinski, E. Ciska, H. Kozlowska
Czech J. Food Sci., 2001, 19(5):182-188 | DOI: 10.17221/6605-CJFS
Tocopherols (T) and tocotrienols (T3) were analysed using HPLC and vitamin E content was calculated in selected cereal grains and their different morphological fractions. Wheat (Triticum aestivum L.) cv. Almari, barley (Hordeum vulgare L.) cv. Gregor, rye (Secale cereale L.) cv. Dańkowskie Złote, oat (Avena sativa L.) cv. Sławko and buckwheat (Fagopyrum esculentum Moench) cv. Kora were used in this study. The highest level of tocopherols was found in dehulled buckwheat and in its fraction of the endosperm with the embryo, where γ-T was found to be the main tocopherol (94.1% and 93.7% of total, respectively)....
Wheat and flour quality relations in a commercial mill
M. Hrušková, K. Hanzlíková, P. Varáček
Czech J. Food Sci., 2001, 19(5):189-195 | DOI: 10.17221/6606-CJFS
The bread-making quality of forty commercial winter wheat samples, grown in the western region of the CzechRepublic, and their flours (white flours with ash content of about 0.5%) prepared in a commercial mill was studied. Standard analytical methods (ash and protein content, wet gluten), amylolytic activity measurement (falling number), rheological investigation (alveograph, gluten index), sedimentation test and laboratory baking test were used for characterization of wheats and flours. In addition NIR method was used to calculate ash, wet gluten, sedimentation value and protein content. Statistically significant correlations were found practically...
Determination of astringent taste in model solutions and in beverages
H. Valentová, S. Škrovánková, Z. Panovská, J. Pokorný
Czech J. Food Sci., 2001, 19(5):196-200 | DOI: 10.17221/6607-CJFS
The astringent taste is important for the sensory quality of beverages. Perception thresholds of two important astringent compounds - tannic acid and (+)-catechin were determined using two procedures. The concentration-intensity dependence was linear at low concentrations and up to medium intensities of the astringent taste if unstructured graphical scales were used, but the saturation threshold was soon attained in the case of tannic acid. Recording the results on printed forms gave similar results as using a touch-sensitive monitor. The optimum tasting was achieved at swallowing after degustation of 5 s. The duration of degustation increased the...