THE INFLUNCE OF SEASON ON THE CASEIN CONTENT AND HYGIENIC QUALITY OF THE RAW MILK

Abstract

Increased somatic cell count (SCC) and a total count of microorganism presented as a colony forming units (CFU) in milk are often associated with mastitis in dairy cows. Alterations appearing in milk with the increased totalcount of microorganism and somatic cell count are mainly addressed to increased pH value, the unfavorable ratio of casein fractions, changes in coagulation capability of milk, reduced yield, and cheese quality. Casein is participating with approximately 82% of the total milk protein, which makes it the most important part of the protein content. Numerous parameters impact on raw milk selection for cheese production, but the most important is thecasein content and hygienic quality of raw milk (total count of microorganism and somatic cell count). During the research, in total of 1.440 raw milk samples were analyzed.  The aim of the research was to determine the impact of the total count of microorganisms and somatic cell count, depending on the season, on changes in raw milk physical-chemical characteristics, with special attention on casein. Raw milk samples were tested with LactoScope FTIR Advanced (Delta Instruments).An obtained result indicates a significant correlation between raw milk microbiological quality and total casein content. Raw milk microbiological quality depends mostly on farm conditions and GHP, and raw milk manipulation until processing. The results obtained from this research indicate the fact that seasonal changes have an impact on the quality and hygienic condition of raw cow's milk.It can be concluded that an increase in somatic cell count, rather than total count of microorganisms, resulted in a reduced protein and casein content in raw milk.