Pasteurised milk is tested by:

Ans: a (Phosphatase test) Ref; Park, 19 ed, p. 522Tests for pasteurised milk:Phosphatase testStandard plate countColiform countOTA test--for detection and estimation of free and combined chlorine in chlorinated water.Benzidine test--chemical test for the detection of blood stainParaffin test--detection of gun powder residuesMethylene blue reduction test--It is an indirect method for detection of micro-organisms in milk.This test is carried out on milk accepted for pasteurizationMethods of pasteurization:Holder or Vat method:In this the milk is kept at 63- 66oC for atleast 30 min and then cooled to 5degCHigh temperature short time method: (HTST)Milk is rapidly heated to temperature of nearly 72degC and held at that temperature for not less than 15 sec and is then cooled to 4degC.Most widely used method now.UHT method / Ultra high temperature method:Milk is rapidly heated usually in 2 stages to 125degC (second stage under pressure.)Thermodynamic bacteria and bacterial spores are resistant towards pasteurization.