Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Science

Committee Chair(s)

Carl A. Ernstrom


Carl A. Ernstrom


Gary Richardson


Von Mendenhall


Ted Gillett


LeGrande Ellis


A linear diffusion test in sedimentation tubes filled with caseinagar gel successfully measured milk clotting enzymes at concentrations of 10-4 to 1 X 10-l rennin units/ml with 95% accuracy. Diffusion rates were unaffected by diluting enzyme samples with whey, 3% NaCl, and water, The distribution of rennet, porcine pepsin, mucor pusillus var Lindt (MP) protease, and rennet-pepsin mixtures between curd and whey was determined on milk coagulated at pH 5.2, 6.0, 6.4, and 6.6. The procedure accounted for 100 + 7% of the added enzymes. The distribution of rennet was pH dependent with 31% and 72% in curd and whey respectively at pH 6.6, and 864 and 174 respectively at pH 5.2. The distribution of MP protease was independent of pH with approximately 154 and 85% in the curd and whey at all pH values. Pepsin behaved similar to rennet but was unstable above pH 6.0. During Cheddar cheese making, 7% and 58% of the original rennet, 6% and 93% of the original MP protease, and 5% and 17% of the original rennet-pepsin mix was active in the curd and whey respectively at dipping. After overnight pressing, 6% of the rennet, 3% of MP protease, and 4% of the rennet-pepsin mix remained active in the cheese. At dipping only 9% of the original pepsin was detected in the whey. Pepsin was unstable at pH values used to release the enzyme from the curd and could not be quantitated.



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