Development of bio-strip based test for ascertain proper milk pasteurization

Abstract

Alkaline phosphatase (ALP) enzyme is naturally present in raw milk which is used as a prominent indicator to determine proper pasteurization in milk. However, determination of ALP activity in milk either time-consuming or required sophisticated instrument facilities that are uncommon in India's rural dairy or collection centers. Present test is based on the ALP reaction with p-nitrophenyl phosphate to release p-nitrophenol and inorganic phosphate in the presence of water. When p-nitrophenol reacts with a certain chromogen, the strip's colour changes from purple to grey, which may be seen with the naked eye. This strip has a nine-month shelf life at room temperature.