Effect of ripening temperature on the quality of low moisture Mozzarellacheese: 1. Composition and proteolysis

摘要

Low-moisture Mozzarella cheese, in duplicate trials, was ripened at 0, 4, 10 or 15 degreesC for 70 d. For all temperature treatments, increasing ripening time resulted in significant (P < 0.05) increases in the level of proteolysis as measured by the levels of pH 4.6 soluble-N (pH 4.6SN) and 5% phosphotungstic acid-soluble N (PTA-N). Urea-PAGE electrophoretograms of the pH 4.6-insoluble cheese extracts showed that increasing the storage temperature resulted in an increase in the extent of degradation of (s1)-CN but had little effect on the degradation of beta -casein. Increasing the ripening temperature resulted in a significant increase in the mean level of pH 4.6SN and PTA-N over the 70 d ripening period. Reverse-phase HPLC (RP-HPLC) of the pH 4.6-soluble and 70% ethanol-soluble fractions of the pH4.6-soluble cheese extracts indicated a heterogeneous array of peptides. The concentration of early-eluting peptides, representing amino acids and small peptides, increased as the ripening temperature was increased.