ISO 5544│IDF 89:2008规定了一种参考方法,用于测定通过酸沉淀或乳酸发酵获得的酪蛋白、酪蛋白酸铵、其与凝乳酶酪蛋白和酪蛋白酸盐的混合物以及未知类型酪蛋白的“固定灰分”(以质量百分比计)。
ISO 5544│IDF 89:2008 specifies a reference method for the determination of the "fixed ash" of caseins, as a percentage by mass, obtained by acid precipitation or lactic fermentation, of ammonium caseinates, of their mixtures with rennet casein and with caseinates, and of caseins of unknown type.