Effects of cold storage on the quality parameters of goat milk

Abstract

The small-scale goat milk production requires its storage, and such operation is allowed by Brazilian laws. This study aimed at evaluating the cooling and freezing effects on physical-chemical and microbiological characteristics of goat milk. However, no variability was verified in average acidity, alcohol stability, density, fat protein, total solids and lactose values after cold storage. Heat instability was not observed in any of the analyzed samples. There was a decreasing tendency in the somatic cell count (SCC) of frozen milk in comparison to fresh and refrigerated milk. The quantification (NMP) of total and thermo-tolerant coliforms varies from < 3 (no growth) to > 1,100 UFC/mL, regardless of the storage method. However, a slightly higher count (p < 0.0001) was observed for total and thermo-tolerant coliforms in the samples kept under refrigeration. In the lacto-fermentation test, digested, flocculated and grooved clots were observed without establishing a correlation between them and the bacterial count. SCC and microbial count are the criteria adopted when paying for the quality of goat milk, and the storage temperature may affect these criteria.