Influence of the frozen storage period on the coagulation properties of caprine milk

Abstract

Coagulation properties of caprine milk frozen for up to 60 days at -27 degrees C were investigated using a rheometer with a vane geometry tool. Coagulation time (CT) and aggregation rate (AR) were estimated during gel formation for 64 min at 1 Hz and 1% strain. Evaluation of curd firmness (CF) was done using frequency spectra of the resulting gels. The data were processed by ANOVA and linear regression (with frozen storage time as independent variable and pH, AR, CT and CF as dependent variables). No statistically significant changes in coagulation properties were found, although the milk pH decreased from 6.64 (non-frozen pasteurised milk) to 6.41 after 60 days of frozen storage. The results of this research showed that the coagulation properties of caprine milk were not significantly altered during 60 days frozen storage. It could be assumed, therefore, that the cheese-making processing properties of caprine milk would also not change.