Date of Award:

1974

Document Type:

Dissertation

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Science

Advisor/Chair:

Carl A. Ernstrom

Abstract

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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27241b0d03c08beee729f5131676414f

Included in

Nutrition Commons

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