Application of qualitative tests for detection of adulterants in sterilized milk and during its subsequent storage

Effect of sterilization of milk and its subsequent storage on performance of qualitative tests used for detection of adulterants in the milk was studied. Some of the most prevalent adulterants viz. detergent, urea, ammonium salt, maltodextrin, starch, glucose, sucrose, gelatin, formaldehyde, hydrogen peroxide, and neutralizers were tested. Control and adulterated samples of milk were sterilized at 121oC for 15min. The samples of sterilized milk were stored at 352oC. The respective qualitative tests were performed for detection of adulterants on 0th, 15th, 45th, and 75th day of the storage. The performance of the qualitative tests varied depending on length of storage period for which samples were stored and chemical nature of the target adulterant spiked in the milk. Practical applicationsAdulteration of milk is serious food safety issue in developing countries. Chemical qualitative tests are one of the most affordable and convenient means for detection of adulteration, particularly in such countries. However some processing treatments like sterilization affect these qualitative tests significantly. Moreover, limited information is available related to effect of such processing treatment on test performance. Hence, evaluation of the effect of such treatment on qualitative test for detection of adulterant in milk is essential.