Brevibacterium linens as an adjunct starter culture in low fat ras cheese [electronic resource].
استخدام الBrevibacterium linens كباديء مساعد في صناعة الجبن الرأس منخفضة الدهن.
- p.1713-1726
Includes references.
The aim of this study was to improve the quality of low fat Ras cheese via the application of adjunct starter culture. Ras cheeses were made from cow's milk standardized to 1.0, 1.5, 2.0. 2.5 and 4.0% fat content. The fat level (4%) corresponds to the control. All milk batches were divided into two portions. The first portion of all batches was manufactured into Ras cheese using yoghurt starter culture. Brevibacterium linens was further added to cheese milks at the level of 0.5% in the second portion. The obtained results reveal that, both contents of the dry matter (OM) and protein (total nitrogen, TNx6.38) of cheese increased as the fat content of cheese milk decreased. The use B. linens was associated with increasing in the DM. protein, fat/DM contents of cheese, those also raised gradually along maturation period for 24 weeks. The water soluble nitrogen, non protein nitrogen, soluble tyrosine, soluble tryptophan, total volatile fatty acids and titratable acidty (T A) contents of cheese decreased as the fat content of cheesemilk was reduced, but they were raised when B. linens was used. While pH value was not affected either by lowering the fat content, or using B. linens, which did not significantly . influence the T A% of cheese. The counts of total bacteria, lactic acid bacteria, proteolytic bacteria and lipolytic bacteria declined as the fat content decreased. On the contrary, those bacterial groups were higher when B. linens was applied. In all cases the bacterial counts were proportionally increased during maturation period until the 12th week and then gradually decreased by prolonging the ripening period there more. Chalky appearance and crumbly texture were obviously noticed with the excessive reduction in the fat content more than 2.5%., The sensory quality, however, improved in the presence of B. linens even in the" cheese made from milk containing 1% fat. Finally, a palatable low fat Ras cheese could sucessfully made from low fat milk using B. linens as an adjunct starter culture.