Physico-Chemical and Bacteriological Changes in Marketed Raw Milk During Its Transportation to Consumers

Abstract

Milk is a nutritious food but at the same time is an excellent medium for the growth of microorganisms. Nearly all the changes in taste, flavour or appearance of raw milk are result of bacterial activities. The activities of these bacteria if pathogenic may cause certain health problems. In this study sixty milk samples collected each from three different consumers and producing areas of Abbottabad city, were analyzed for physico-chemical properties and microbial analysis. The mean scores of colour, taste and flavour for marketed raw milk and fresh milk were 7.03, 5.86, 5.71 and 7.06, 7.15, 6.75, respectively. 30% of the samples of marketed raw milk gave positive response to alcohol precipitation test and all samples of fresh milk gave negative response to alcohol precipitation test. The mean value of specific gravity for marketed raw milk and fresh milk was 1.023 and 1.033 respectively. The mean value of pH for marketed raw milk was 6.53 and 6.71 for fresh milk. Fat percentage results showed that all marketed raw milk samples analyzed were below the required standards for buffalo milk. Total bacterial count revealed mean of 7.29 x 10 10 /ml for marketed raw milk and 5.53 x 10 8 /ml for fresh milk. However all the samples contained total count above the standard i.e., 2 x 10 5 to 5 x 10 6 /ml and all the samples were of very poor quality and placed in grade D. The present study indicated that qualitative and quantitative changes during transportation of milk to consumers were due substandard production of fresh milk and probably due to adulteration.