NF ISO 23318, V04-361 (02/2024)

This document specifies the method for determining the fat content. The method is applicable: a) to raw milk (cow, sheep, goat), low-fat milk, skimmed milk, chemically preserved milk and treated liquid milk; (b) dry dairy products (for example, whole milk powder, partially skimmed, skimmed; milk permeate powder; whey powder; mixture of milk powder and vegetable fat; infant formula based on milk powder); (c) raw cream, processed cream and sour cream; For the following products, precision data are provided in Annex H. These precision data are derived from interlaboratory studies not conforming to the requirements of ISO 5725-2 with regard to the number of samples ( <6) and the number of participating laboratories (<8). (d) evaporated milk and sweetened condensed milk (for example, sweetened and unsweetened liquid condensed milk); e) whey cheese, as defined in CODEX CXS 284-1999; (f) liquid whey and buttermilk; (g) ice creams and ice cream mixes made from milk; h) concentrated liquid foods for infants. The method does not apply in the following cases: — for b), when the powder contains lumps which do not dissolve in ammonium hydroxide solution, in which case a characteristic odor is given off and the result of the determination is too low. In these situations, a method using the Weibull-Berntrop principle is suitable, for example ISO 8262-3|IDF 124-3; — for (c), the method is not applicable to sour creams containing starch or other thickening agents. When fat separation or degradation occurs, a method using the Weibull-Berntrop principle is suitable, for example ISO 8262-3|IDF 124-3; — for e), products which do not dissolve completely in an ammonium hydroxide solution, giving rise to a determination result that is too low. In the case of these products, a method using the Weibull-Berntrop principle is suitable, for example ISO 8262-3|IDF 124-3; — for g), ice creams and ice cream mixes made from milk in which the level of emulsifier, stabilizer or thickening agent, or egg or fruit yolk, or combinations of these constituents, makes the Röse-Gottlieb method unsuitable. In the case of these products, a method using the Weibull-Berntrop principle is suitable, for example ISO 8262-2|IDF 124-2; — for h), products which do not dissolve completely in ammonium hydroxide due to the presence of starch or dextrin at mass fractions greater than 5 % (dry matter), or the presence of lumps. In the case of these products, a method using the Weibull-Berntrop principle is suitable, for example ISO 8262-1|IDF 124-1.
(Automatic translation from French)