Impact of Adulteration on Physico-chemical Characteristics of Marketed Raw Milk

Abstract

This study was conducted to determine the impact of adulteration on physico-chemical and coliforms content of marketed raw milk. For this purpose, 300 milk samples were collected from urban and peri-urban localities of Jhang, Pakistan. The results showed that 13.3%, 9.7%, 9%, 8.3% and 5.7% of the tested milk samples were positive for cane sugar, formalin, boric acid, H2O2 and urea, respectively besides the highest adulteration of water (95%). Other adulterants included soap (4.7%), sodium chloride (3.7%) and quaternary ammonium compounds (3.3%). The incidence of cane sugar and starch adulteration was highest in winter while formalin and H2O2 in summer season. The compositional quality of milk was also deteriorated by relatively lowered concentrations of lactose, fats, total solids, solids-not-fat (SNF) and proteins. Likewise, the pH and freezing point of contaminated milk samples were comparatively higher than the corresponding standard values. Furthermore, the adulterated milk samples were highly contaminated with E. coli (42.5%) and Enterobacter aerogenes (27.5%) as compared to non-adulterated milk. It was concluded that milk adulterationin the study area predominates round the year badly deteriorating the physico-chemical characteristic of milk besides contaminating it with injurious adulterants and water-borne pathogens posing potential health risks to the consumers.