The legal standards for the process of pasteurization of milk supplies have been well defined and clarified. Likewise, the process is generally accepted as a safety measure particularly in city milk supplies and often in the home.
The question as to whether or not a milk has been adequately pasteurized has long been a problem for organizations engaged in dairy control work. Local inspection at the plant depends on observation of the charts used to record the length of time and the temperature. The accuracy of these charts depends on the care and attention given by the pasteurizing management and employees. The laboratory, however, has looked for a simple objective test in an effort to determine when the finished product is satisfactory and safe. To accomplish this, considerable attention has been given to the enzymes amylase and phosphatase which are present in raw milk. Rothenfusser1 worked out a
Geiger JC, Davis C. THE USE OF THE PHOSPHATASE TEST IN DETECTING UNDERPASTEURIZED MILK IN SAN FRANCISCO. JAMA. 1937;109(17):1363. doi:10.1001/jama.1937.92780430002009a