Assessment of physicochemical, microbiological, and quality characteristics of raw standardized milk in northern parts of India

The focus of study was to investigate physicochemical, microbiological, and quality characteristics of raw standardized milk collected from different northern parts of India. Results showed that physicochemical test values for pH, acidity, moisture, fat, SNF, total soluble solids, protein were varied from 6.62 to 6.66, 0.133% to 0.121%, 84.17% to 86.01%, 5.09% to 6.59%, 8.47% to 9.23%, 13.56% to 15.82%, 36.45% to 36.78%, and 0.61% to 0.73%, respectively. These results were in accordance with Codex International Standard and the Food Safety and Standards Authority of India. The Reichert-Meissl value, Butyro-refractometer reading, and sodium content of raw standardized milk varied from 28.76% to 29.36%, 41.31% to 41.63%, and 432 to 597 mg/L, respectively. Various adulterants tests were performed for different milk samples; negative results were obtained for all but 2 samples, which had adulterants such as sugar, skim milk, and antibiotic residues. The results of melamine and aflatoxin M₁ of standardized milk varied between 58.17 and 90.83 mg/100 mL and 0.17 and 1.26 µg/kg, respectively. Microbiological analysis showed that in 6 samples of standardized milk, the aerobic plate count and SCC were found to be higher than the upper limit set by the Bureau of Indian Standards (i.e., 10 × 10⁵ and 25 × 10⁴, respectively). Two samples of standardized milk contained higher melamine, TS, and psychotropic count as compared with world standards. The sensory scores for 3 of the standardized milk samples (samples L-1, L-8 and L-9) varied from 5 to 8. This study helps to analyze the quality of milk, which is being tainted with various adulterants because of a lack of supervision, unsanitary facilities, or for financial gain.