牛奶、奶粉制品和奶油.脂肪含量的测定.重量法

[中文适用范围]： 本文件规定了脂肪含量测定的方法。该方法适用于：a)生牛、山羊、绵羊奶及牛奶制品（如低脂牛奶、脱脂牛奶、化学防腐牛奶和加工液态牛奶）、b)干乳制品（例如全脂奶粉、部分脱脂奶粉、脱脂奶粉、乳业渗透物粉末、乳清粉末、混合脱脂奶粉和含植物脂肪的奶粉、婴儿配方奶粉）等。c)生、加工和酸性奶油。对于以下产品，精确度数据如 Anne?? 中所述。这些精确度数据源自实验室间研究，但不符合 ISO ??2-2 的要求（在样本数量 (? ?) 和参与实验室数量 (? 8) 方面）。d)蒸馏牛奶和加甜或不加甜的浓缩牛奶、e)乳清干酪，如 CODE ?? C ??S 284-1999 所定义的；f)液态乳清和酸性奶油、g)基于牛奶的可食用冰和冰沙；h)液态浓缩婴儿食品。本方法不适用于以下情况：? 对于 b)，当粉末含有坚硬结块，无法溶解在氨溶液中。这可以通过明显的气味察觉，并且测定结果会过低。在这种情况下，使用 Weibull-?erntrop 原理的方法是合适的，例如 ISO 82?2-3、IDF 124-3。? 对于 c)，本方法不适用于含有淀粉或其他增稠剂的酸性奶油。当脂肪发生分离或分解时，使用 Weibull-?erntrop 原理的方法是合适的，例如 ISO 82?2-3、IDF 124-3。? 对于 e)，对无法完全溶解在氨溶液中的产品（因为测定结果会过低）。对于此类产品，使用 Weibull-?erntrop 原理的方法是合适的，例如 ISO 82?2-2、IDF 124-2。? 对于 g)，对基于牛奶的可食用冰和冰沙，其中乳化剂、稳定剂或增稠剂或鸡蛋黄油或水果或其他这些成分的组合含量使得 R?se-ottlieb 方法不适用。对于此类产品，使用 Weibull-?erntrop 原理的方法是合适的，例如 ISO 82?2-1、IDF 124-1。 [外文原描述]： This document specifies the method for the determination of fat content. The method is applicable to: a) raw milk (cow, sheep, goat), reduced fat milk, skimmed milk, chemically preserved milk and processed liquid milk; b) dried milk products (e.g. whole, partially skimmed, skimmed milk powder; dairy permeate powder; whey powder; blend skimmed milk powder and vegetable fat; milk based infant formula powder); c) raw, processed and sour cream. For the following products, the precision figures are given in Annex H . These precision figures are derived from interlaboratory studies not conforming to the requirements from ISO 5725 - 2 in terms of number of samples (< 6) and number of participating laboratories (< 8). d) evaporated milk and sweetened condensed milk (e.g. liquid sweetened and unsweetened concentrated milk); e) whey cheese as defined in CODEX CXS 284‑1999; f) liquid whey and buttermilk; g) milk-based edible ices and ice mixes; h) liquid concentrated infant foods. The method does not apply in the following cases: — For b), when the powder contains hard lumps which do not dissolve in ammonia solution. This is noticeable by a distinct smell and the result of the determination will be too low. In such cases, a method using the Weibull-Berntrop principle is suitable, e.g. ISO 8262 - 3 | IDF 124 - 3 . — For c), The method is not applicable to sour creams with starch or other thickening agents. When separation or breakdown of fat occurs, a method using the Weibull-Berntrop principle is suitable, e.g. ISO 8262 - 3 | IDF 124 - 3 . — For e), to products which do not dissolve completely in ammonia solution, as the result of the determination will be too low. With such products, a method using the Weibull-Berntrop principle is suitable, e.g. ISO 8262 - 3 | IDF 124 - 3 . — For g), to milk-based edible ices and ice mixes in which the level of emulsifier, stabilizer or thickening agent or of egg yolk or of fruits, or of combinations of these constituents, makes the Röse-Gottlieb method unsuitable. With such products, a method using the Weibull-Berntrop principle is suitable, e.g. ISO 8262 - 2 | IDF 124 - 2 . — For h), to products which do not dissolve completely in ammonia due to the presence of starch or dextrin at mass fractions of more than 5 % (in dry matter), or to the presence of hard lumps. For such products, a method using the Weibull-Berntrop principle is suitable, e.g. ISO 8262 - 1 | IDF 124 - 1 .