ISO 6732:1985

Is applicable to milk, skimmed milk, whey, buttermilk, plain and skimmed yogurt, evaporated milk, sweetened condensed milk, dried whole and skimmed milk, dried whey and dried buttermilk, cream and butter, butterfat, ice-cream, cheese of various ages and processed cheese, caseins, caseinates and coprecipitates. The principle of determination consists in digesting the organic material with a mixture of nitric and sulfuric acids.