STUDIES ON ASEPTIC RAS CHEESE SLURRY | ||||
| Journal of Food and Dairy Sciences | ||||
| Article 4, Volume 31, Issue 9, September 2006, Page 5821-5831 PDF (170.59 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jfds.2006.236860 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Aisha El Attar | ||||
| Dept. of Dairy Science and Technology. Fac. of Agric... Alex. Univ. Egypt | ||||
| Abstract | ||||
| The proteolytic and autolytic activities in buffer system of six strains of lactic acid bacteria isolated from Egyptian dairy products were examined. The selected strains (Lactococcus lactis sub sp. iecris 04RM. Lactococcus lactis sub sp. iaciis 608M. Lactobaciiius saiiverius 194KC. Lactobaciiius mamnosus 56R. Enterococcus iaeciurn 151D and Enterococcus faecium 174RM) were blended into freshly made starter—free Ras cheese (acidified with gluoono- o -lactone. GDL) to town slum'es that were ripened anaerobically at 30°C for 5 days. Results showed relatively constant values of moisture and fat contents in slurries. while pH values decline after five days of ripening. The highest release of free fatty acids was noticed in four slurries (Eni. faeciurn 174RM. Lb. saiiverious 194KC. Lb. mamnosus 56R and Lo. iectis subsp. iaciis EDEN). on the contrary. the mixture of strains in slum‘es showed a moderate release of free fatty acids. Peptidase activities in the proteolytic system of the tested Ras cheese sium‘es have been demonstrated from the Cadmium- ninhydrine (Cd- ninhydrine) reaction of water-soluble extract. The highest values of free amino acids (FAA) were noticed in the individual tested Iactobacillus strains. Whereas. sluny containing mixed strains showed a moderate release of FAA (Lb. seiivarious 194KC + Lc. lactis subsp. iactis 64RM). Proteolysis of studied slun-ies was also qualitatively followed by using Urea- poiyacrylamide gel electrophoresis ten. 'nnlque. Casein degradation an‘ses quickly in slurries during 5 days of ripening. tin-casein hydrolysed to small weight peptides. while. the B- casein is apparently not degraded. The organoleptic evaluations were correlated with the release of free amino acids and aminopeptidase activity. So. the present investigation emphasizes the importance of proteolytic system of selected strains in improving the flavour and texture of cheese. | ||||
| Keywords | ||||
| Aseptic Ras cheese slun'y. Proteolysis. Lactic acid bacteria. Ripening | ||||
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