# First Commission Directive of 13 November 1979 laying down Community methods of analysis for testing certain partly or wholly dehydrated preserved milk for human consumption (79/1067/EEC), Division 3: PRINCIPLE

Extent: E+W+S+N.I.

Fat, protein and lactose are simultaneously removed from a solution of the sample by addition of copper sulphate and calcium hydroxide followed by filtration.
The lactic acid and lactates in the filtrate are converted into acetaldehyde by concentrated sulphuric acid in the presence of copper II sulphate.
The lactic acid content is determined colorimetrically using p-hydroxydiphenyl.
The lactic acid and lactates content is expressed as mg of lactic acid per 100 g of solids-non-fat.

---
Source: https://www.legislation.gov.uk/eudr/1979/1067/annex/II/division/7/division/3 (the official version)
Page: https://openlegislation.uk/eu-directive-1979-1067/annex-II/division-7/division-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.