Diffuse Reflectance Profiles of Eight Milk-Clotting Enzyme Preparations

Authors

  • Z. USTUNOL,

    1. Author Ustunol is with the Dept. of Food Science & Human Nutrition, Michigan State Univ., East Lansing, Ml 48824-1224. Author Hicks is with the Food Science Section, Dept. of Animal Sciences, Univ. of Kentucky, Lexington, KY 40546-0215. Author Payne is with the Dept. of Agricultural Engineering, Univ. of Kentucky, Lexington, KY 40546.
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  • C. L HICKS,

    1. Author Ustunol is with the Dept. of Food Science & Human Nutrition, Michigan State Univ., East Lansing, Ml 48824-1224. Author Hicks is with the Food Science Section, Dept. of Animal Sciences, Univ. of Kentucky, Lexington, KY 40546-0215. Author Payne is with the Dept. of Agricultural Engineering, Univ. of Kentucky, Lexington, KY 40546.
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  • F. A. PAYNE

    1. Author Ustunol is with the Dept. of Food Science & Human Nutrition, Michigan State Univ., East Lansing, Ml 48824-1224. Author Hicks is with the Food Science Section, Dept. of Animal Sciences, Univ. of Kentucky, Lexington, KY 40546-0215. Author Payne is with the Dept. of Agricultural Engineering, Univ. of Kentucky, Lexington, KY 40546.
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  • Journal article No. 90-5-70 of the Kentucky Agricultural Experiment Station.

ABSTRACT

Eight milk-clotting enzyme prepartations were standardized to equal clot time and used to coagulate pasteurized whole milk. Diffuse reflectance profiles were monitored for 60-min using a fiber optic sensor sensitive to infrared light at 950 nm. Modified M. miehei and M. pusillus protease, recombinant chymosin and calf rennet produced similar profiles. Rates of increase in diffuse reflectance were E. parasitica recombinant chymosin > calf rennet > modified M. miehei, M. pusillus var. Lindt > 50:50 blend of calf rennet and bovine pepsin > unmodified M. miehei > pepsin. Monitoring milk coagulation as described may be useful during cheese making and allow setting optimal conditions for milk-clotting enzyme preparations.

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