Incorporation of 10, 15 and 20% unsalted sour buttermilk into buffaloe's or
cow's milk or into mixture of buffaloe's and cow's milk (50% : 50%) was chemically
and rheologically studied.
Acidity of buffaloe's or cow's milk or milk mixture increased proportionally as
buttermilk was increased, while pH, TS, fat and TN of milk decreased.
Replacement of buffaloe's or cow's milk or the milk mixture by 10, 15 or 20%
buttermilk decreased rennet coagulation time (ReT) and curd tension and increased
curd syneresis. Buttermilk alone was not coagulated by liquid calf rennet.
The above results showed the possibility of making Ras cheese by adding
15% unsalted buttermilk to the mixture of buffaloe's + cow's milk (50% : 50%).
Adding 15% buttermilk to the mixture of milk decreased yield, pH, fat, fat / OM,
TN, and TN/OM of Ras cheese during ripening, while acidity, moisture, salt, salt / OM,
soluble nitrogen (SN), SN!TN, non-protein nitrogen (NPN), NPN !TN, soluble tyrosine
(S.Tyr.), soluble tryptophane (S.Try) and TVFA of Ras cheese increased.
Incorporation of 15% buttermilk into a mixture of buffaloe's + cow's milk decreased
saturated fatty acids (SFA) and increased unsaturated fatty acids (USFA) in Ras
cheese.
Using microbial rennet (Formase) in Ras cheese making decreased yield,
moisture, and SFA contents and increased acidity, fat, TN, SN, NPN, S.Tyr, S.Try,
TVFA and USFA in resultant cheese as compared with liquid calf rennet cheese.
Fat and protein losses in whey were higher in Ras cheese containing
buttermilk as compared with control cheese. Fat and protein recoveries were lower in
Ras cheese made using Formase than that made from liquid calf rennet.
Incorporation of 15% unsalted sour buttermilk improved the organoleptic
properties of Ras cheese made from buffaloe's + cow's milk, but organoleptic
properties were slightly lower in Formase cheese than those cheese made with liquid
calf rennet.. Also, adding 15% buttermilk to cheese milk increased the economic
profit of the resultant Ras cheese.