Template-Type: ReDIF-Article 1.0 Author-Name: N.A. Olasupo Author-Name: U. Schillinger Author-Name: C. Franz Author-Name: W.H. Holzapfel Title: Enterocin NA: A Bacteriocin Produced by Enterococcus faecalis BFE 1057 Isolated from a Nigerian Fermented Dairy Product Abstract: Enterococcus faecalis BFE 1057 isolated from a Nigerian fermented dairy product ('nono') produced a bacteriocin designated enterocin NA. It was found inhibitory towards Lactobacillus, Enterococcus and Listeria strains. Enterocin NA was inactivated by proteolytic enzymes, and resistant to heating at 80 °C for 30 min and active at pH 2.0 to 8.0. Its molecular weight was estimated by ultrafiltration to be above 3000 daltons. The ability of this bacteriocin to inhibit Listeria is of potential interest in food safety and enterocin NA may have future applications as a food preservative. Keywords: bacteriocin, Enterococcusfaecalis, fermented foods, enterocin, nono Journal: Czech Journal of Food Sciences Pages: 1-4 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/9997-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/9997-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:9997-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: L. Karasova Author-Name: P. Rauch Author-Name: L. Fukal Title: Sestavení kompetitivní enzymové imunoanalýzy pro stanovení α-laktalbuminu a β-laktoglobulinů kravského mléka Abstract: Polyclonal antibodies were raised against three immunogens- a-lactalbumin (LA), -lactoglobulin A (LGA) and B (LGB). Using these antibodies the procedures of an indirect competitive enzyme immunoassay (ELISA) were constructed, optimized a nd characterized for determination of indi vidual immunogens. It was found that ELISA of LA is very specific without any inter­ ferences of other whey proteins. However, in ELlSAs of both lactoglobulins A and B were demonstrated very high interferences of the other genetic varian t (cross-reactivities 20-280% depending on antibody and immu nogen). An excellent sensitivity of ELISA for all proteins (detection limits for LA, LGA and LGB were 13, 0.4 and 54 ng/ml, respectively) makes it possible to analyze milk samples diluted more than 1000 times. Average values of variation coefficient were in the range 16-27%. A compari­ son of whey protein determinations in raw cow's milk by ELISA and by capillary electrophoresis resulted in the best similarit y in results of LA concentration. The decrease of LA, LGA and LGB concen trations was detected by using capillary electrophoresis for an analysis of whey from heat-treated milk, while ELISA of the same milk sample showed the increase of LGB immunoreac­ tivity to 700%. Keywords: α -lactalbumin, β -lactoglobulin, whey proteins, ELISA Journal: Czech Journal of Food Sciences Pages: 5-14 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/10014-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/10014-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:10014-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: G. Greif Author-Name: M. Greifova Author-Name: J. Dvoran Author-Name: J. Karovicova Author-Name: V. Buchtova Title: Štúidium rastu a produkcie biogénnych amínov niektorými mikroorganizmami za modelových podmienok Abstract: The study was aimed at the growth of selected strains from the family Enterobacteriaceae (Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoniae) in meat-peptone (MPB) broth and cabbage juice at different cultivation temperatures, and at the production of biogenic amines (cadaverine, putrescine, histamine). Bacterial growth was evaluated on the basis of specific growth rate (IJm) and lag phase (A.) calculated from growth curves. Cadaverine was produced as the first amine in MPB and cabbage juice by all studied st rains at the cultivation temperatures and at Jiving cell densities 10 6 KTJ/cm3. Putrescine was produced by E. coli only in both substrates at the cultivation temperatures. Histamine was produced by E. coli at 18 °C in cabbage juice and by Enterobacter aerogenes in both substrates at the cultivation temperatures. Keywords: cadaverine, putrescine, histamine, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae Journal: Czech Journal of Food Sciences Pages: 15-21 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/10015-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/10015-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:10015-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: P. Novotna Author-Name: M. Houska Author-Name: V. Sopr Author-Name: H. Valentova Author-Name: P. Stern Title: Vliv smykové viskozity a elasticity na senzorickou viskozitu modelových kapalných potravin Abstract: The shear flow rheological properties of sugar solutions (70% w/w concentration) modified by different cellulose derivatives have been measured. Thickeners were expected to cause the viscoelastic behaviour of the resulting sol ution. Therefore, the elastic rheological parameters were measured by oscillatory shear technique (phase angle, elastic modulus) and also the first normal stress difference N1. The increase of thickener concen tration caused a moderate increase of non-Newtonian behaviour in the shear flow. The sensory viscosity (ra nged between 0 and 100%) was evaluated by five different methods - as an effort for stirring with teaspoon, time for flowing down the spoon, slurping from spoon, compression between tongue and palate and swallowing. The influence of shear viscosity and first normal difference on sensory viscosity was tested. Correlation procedu re between change of sensory viscosity .tlSE and change of shear viscosity .tlJ.Iz showed that only for swallowing there is a statistically evident de­pendence. The correlation between change of sensory viscosity t.SE and first normal stress difference N1 is not statistically evident. For all the methods of sensory evaluation the dependence between these parameters is only weak and indirect (with increasing normal stress difference the sensory viscosity is decreasing). Keywords: derivatives of cellulose, elasticity, sensory viscosity, shear viscosity, correlation Journal: Czech Journal of Food Sciences Pages: 23-30 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/10016-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/10016-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:10016-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Paiakova Author-Name: O. Burdova Author-Name: P. Turek Author-Name: A. Laciakova Title: Senzoricke hodnotenie jogurtov vyrobenych z kravského, ovčieho a kozieho mlieka Abstract: In order to identify sensorial properties of yoghurts, we prepared experimentally yoghu rts from cow, sheep and goat milk at keeping common technological procedures. On the basis of reached results, yoghu rt made of sheep milk was evaluated as the one of the highest quality, followed by yoghurt made of cow milk with the one made of goat milk in the last place. Keywords: yoghurt, sensorial evaluation, cow, sheep and goat milk Journal: Czech Journal of Food Sciences Pages: 31-34 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/10017-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/10017-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:10017-CJFS Template-Type: ReDIF-Article 1.0 Author-Name: R. Uherova Author-Name: M. Horkulicova Author-Name: M. Mikusova Title: Relevance of folic acid fortification of foods in the nutrition of women and children Abstract: Folic acid and its biologically active derivates (folacin or folates) rank among the B-group vitamins due to their hydrophilic character. This acid occurs in nature either in the free form or it is bound to proteins or polysaccharides. Folic acid belongs to the group of vitamins which, in the past were not considered important because the relevance of the acid in biological processes of the living cell has been discovered by the scientific research only in recent years. Folates play an important role as co-enzymes in the synthesis of RNA, DNA, proteins and of some essential amino acids. Therefore they are inevitable for the haematopoiesis, growth and reproduction of cells. In this sense a widely oriented research named "Maternal Folate Status" is proceeding in the U.S.A., Australia and France. Keywords: folic acid, Maternal Folate Status, dietery deficiency, fortification Journal: Czech Journal of Food Sciences Pages: 35-39 Volume: 17 Issue: 1 Year: 1999 DOI: 10.17221/10027-CJFS File-URL: http://cjfs.agriculturejournals.cz/doi/10.17221/10027-CJFS.html File-Format: text/html Handle: RePEc:caa:jnlcjf:v:17:y:1999:i:1:id:10027-CJFS