RAW COW MILK QUALITY: PHYSICOCHEMICAL, MICROBIOLOGICAL, AND SEASONAL VARIATION

Abstract

Milk serves as a vital source of essential nutrients in human diets and must be safe for consumption. In the dairy industry, it is crucial to analyze the physicochemical and microbiological properties of raw cow milk (RCM) throughout the year to gather fundamental information, as milk quality significantly influences the final quality of dairy products. This study aimed to investigate the physicochemical and microbiological properties of 60 RCM samples collected from 15 primary milk collection centers in Qazvin, Iran, and assess the impact of seasonal variation on these properties. The study discovered that the RCM samples contained >7 Log10 cfu/mL of Staphylococcus aureus, total coliform count, aerobic mesophilic plate count, and mold and yeast in 15%, 30%, 37%, and 28% of the samples, respectively. The results indicated that aerobic mesophilic plate count, mold and yeast, total coliform count, and Staphylococcus aureus were higher in warmer seasons compared to colder seasons. Furthermore, the study revealed that the average pH, freezing point, solid-not-fat, and protein content were higher in warm seasons, while the average acidity, lactose, and fat content were higher in cold seasons. The physicochemical and microbiological properties of RCM in the Qazvin region were found to be below the acceptable quality value. Although seasonal variation throughout the year affected the microbial and physicochemical quality of RCM, the differences were not statistically significant (p>0.05), except for the solid-not-fat value in winter (p<0.05).