254. The determination of pH in milk and whey by means of colour indicator paper

Abstract

Lyphan paper M 25 can be used for pH measurements in milk and whey in the pK range 5·4—6·6. As a rule the error does not exceed 0·1 pH.In very acid milk and whey (pH < 5·4) lyphan paper of the L series may be used. Generally the deviation does not exceed -0·2 pH. In alkaline milk and whey lyphan paper cannot be used.In milk and whey from cows infected with mastitis M 25 may be used unless the pH exceeds 7.