MULTIVARIATE ANALYSIS IN ASSESSMENT RELATIONSHIPS BETWEEN MILK CHARACTERISTICS INFLUENCED BY THE SEASONAL VARIATIONS

Abstract

The present research aimed to investigate the effects of seasonal variation on microbiological and technological characteristics of raw cow milk from Suceava County. The cow milk samples were collected and investigated during four seasons in three years consecutively. The first period  was the winter season covering the months December – January – February, the second one was the spring season covering the months March – April – May, the third  was the summer season covering the months June – July – August and the fourth period  was the autumn season covering the months September – October - November. Milk characteristics measurements were examined by multivariate data analysis, using Principal Component Analysis (PCA). The analysis of the principal components sheds light on the correlations between the characteristics of the raw cow’s milk, similarities and differences among these in four seasons. The values of the correlation coefficients indicate positive relations between the number of total germ and somatic cell count during spring and summer seasons, between protein content and solids non fat during autumn season. Regarding relationships amongst milk characteristics influenced by the seasonal variation, negative correlations were obtained between fat content and somatic cell count in spring season, between lactose content and somatic cell count in winter and autumn seasons, between somatic cell count and solids non fat content in autumn season.