Seliwanoff test : detecting milk adulteration

                                        Milk Adulteration

             The most common type of adulteration is done by water. Cane-sugar ,starch,sodium chloride and formalin are also used for adulteration.Formalin is used to preserve the milk.

                                          Qualitative Test for detection of milk adulteration

          Detection of cane-sugar in milk 

          Seliwanoffs test

          Requirements:

                                 Resorcinol solution (0.5%)--------->Seliwanoff reagent

         Add 0.5 gram of resorcinol  (powder) in 35 ml of concentrated Hcl and with addition of distilled water form a solution of 100 ml.
          Principle:
                            HCL     +        Fructose    ----------------->  dark red colour solution
          Procedure:
                            Take 1 ml milk sample in a test tube.
                             Add the 1 ml of resorcinol solution in given test tube.
                             Mix the solutions thoroughly.
                             Place the test tube in a boiling water bath for 5 to 10 minutes.
          Result: 
                       Red colour  --------------> test is positive ( sucrose is present in milk )
                       No colour    --------------> test is negative ( sucrose not present in milk )