Is applicable to sweetened condensed milk of normal composition prepared from whole, partially skimmed or skimmed milk and sucrose only and containing no altered succrose. The principle consists in treating the sample with ammonia, neutralizing and clarifying by addition of zinc acetate and potassium hexacyanoferrate(II). This is following by filtration and determination of the optical rotation on part of the filtrate while another part of it is subjected to inversion by mild acid hydrolysis of the sucrose. After inversion the optical rotation is determined and from its change on inversion the sucrose content is calculated.
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