Evaluation of adulterations in raw and pasteurized milk samples, marketed in Birjand, Iran

Milk is a valuable food,that contains essential nutrients for the body,but this product is very perishable and has a short shelf life,so various adulterations may be done in it in order to more profit and increase the shelf life and also to covering the signs of spoilage.In this cross-sectional study,totally80samples(64samples of raw milk and16samples of pasteurized milk)were collected randomly from Birjand markets. All samples were tested in the food laboratory of South Khorasan provincial of standard and industrial research service for adulterations such as adding hydrogen peroxide,formalin, sodium hypochlorite,sodium bicarbonate,salt, starch and water to milk and removing the milk fat.Results of this study showed that water was not added to any of raw and pasteurized milk samples.The mean of fat and salt in raw milk samples was significantly higher and lower than the standard limits,respectively(P<0.001).Salt was not found in pasteurized samples. The mean of milk acidity after boiling,compared with before boiling, both in raw and pasteurized milk decreased significantly(P<0.05), but this decline was less than 1˚dornic.The mean of fat and salt in raw milk samples was significantly higher than pasteurized milk samples(P<0.001)but in terms of acidity before and after boiling,significant difference was not observed in raw and pasteurized milk samples(P>0.05).In terms of hydrogen peroxide,formalin,sodium hypochlorite and starch,any adulterations were not found in this study. Fortunately,the results of this research showed that in all samples of raw and pasteurized milk which collected from Birjand none of above mentioned adulterations was done and in this respect all samples were in appropriate conditions