إضافة بروتينات الشرش المدنترة إلى الحليب البقري أو الخثرة و تأثيرها على بعض الخواص الكيميائية لجبن الراس خلال فترة الانضاج

Abstract EN

The study aimed at determining the effect of addition of whey proteins On some of the chemical properties of Ras cheese during the ripening.

These proteins had been used and added to cow، s milk and cheese curd at 1 and 2 % (Weight / Weight) after denaturation.

The results indicated that the adding of these proteins lead to increase the percentage of acidity, the highest increase was in third – treatment at adding 2% (Weight / Weight) of whey proteins to milk while it was ( acidity percentage) 2.47% At the end of the ripening, as well as the use of these proteins result in increasing the rate of total solids, the highest increase was in fifth – treatment at adding 2% (Weight / Weight) of denatured whey proteins to cheese curd which was 53.98% at the beaning of industry, adding denatured whey proteins resulted in a small increasing in fat rate and the rates were close at beaning of industry range from 27.4% to 28.7% , while the pH had been decreased Reaching 4, 58 at the end of the ripening of the third transaction which is normal due to the increased acidity.

whilst there was a clear increase in the rate of total nitrogen when these proteins had been added, the highest increase was in fifth – treatment at adding 2% (Weight / Weight) of denatured whey proteins to cheese curd which was 3.42 % at the beaning of industry, finally there was an increase in the rate of non-protein nitrogen when denatured whey proteins had been added, the highest increase was in fifth – treatment at adding 2% (Weight / Weight) of whey proteins to cheese curd, which was (rate of non-protein nitrogen) 0.090% at the beaning of industry.

While at the ripening period there was a clear increase in the rate of acidity, solids, total nitrogen, non-protein nitrogen for all treatments when the ripening period had been increased to 90 days which was the end of ripening process while the fat rate was a little increase.