A study of some factors influencing the rennet curd tension of milk and casein sols

The physical character of this curd of milk is of primary importance with reference to the quality, texture and body of some dairy products. Curd tension measurements may indicate the chemical and physical conditions of certain proteins in milk and aid in determining the curd making properties of casein.

Much research and investigation has been devoted to the use of the curd tension test as a measure of the curd forming properties of milk. The test have been important in the study of soft curd milk for infant feeding and has indicated to some extent the efficiency of homogenisation of milk.

Recent studies reported by Merrill (41) have shown that the Hill (4) curd tension test (with pepsin-hydrochloric acid coagulant) is capable of predicting the cottage cheese making qualities of nonfat dry milk lids. The rennet curd tension test (14) was found to be more reliable than the Hill curd tension test for indicating heat treatments of skimmilks and nonfat dry solids. Comparison of test results (14) showed that the rennet curd tension test is as reliable as the Harland-Ashworth (24) method for determining the heat treatments.

With this information at hand the rennet curd tension test has been used in this study to evaluate the influence of certain factors affecting the curd firmness of milks and caseinate sols.