Physical Quality of Raw Milk Marketed in and Around Guwahati City, Assam, India

Introduction: Milk, a nutritionally complete food, is susceptible to contamination throughout the supply chain—from production to consumption. Ensuring its physical quality is crucial for safeguarding public health. Problem: In India, particularly in urban and peri-urban regions like Guwahati, the quality of raw milk often varies and may not meet prescribed legislative standards. Aim: This study aimed to assess the physical quality of raw cow milk samples collected from various locations in and around Guwahati, Assam, India. Methodology: A total of 200 pooled raw cow milk samples were collected from 25 different locations in and around Guwahati during 2015–2016. Physical quality parameters evaluated included titratable acidity, pH, specific gravity, fat content, solids-not-fat (SNF), and the Clot on Boiling (COB) test, following standard procedures. Results: The milk samples exhibited titratable acidity ranging from 0.14% to 0.20% lactic acid, pH between 5.60 and 6.91, specific gravity from 1.024 to 1.030, fat content between 1.57% and 3.55%, and SNF ranging from 6.634% to 8.350%. All parameters showed highly significant (P<0.01) variation among the different locations. All 200 samples tested negative in the COB test, indicating no coagulation on boiling. Conclusion: The study revealed that a substantial portion of raw milk samples failed to meet established physical quality standards, posing potential public health concerns. These findings underscore the need for improved monitoring, regulatory interventions, and public awareness to ensure milk safety and quality.