# Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed (Text with EEA relevance), Division 6.1: Measurement by polarimeter

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

Starch content (%)=2 000P−P'α20°DPTotal optical rotation in angle degrees
P'Optical rotation in angle degrees of the substances soluble in 40 % (V/V) ethanol
α20°DSpecific optical rotation of pure starch. The numerical values conventionally accepted for this factor are the following:
+185,9o:
rice starch
+185,7o:
potato starch
+184,6o:
maize starch
+182,7o:
wheat starch
+181,5o:
barley starch
+181,3o:
oat starch
+184,0o:
other types of starch and starch mixtures in compound feed

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Source: https://www.legislation.gov.uk/eur/2009/152/annex/III/division/L/division/1/division/6/division/6.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-152/annex-III/division-L/division-1/division-6/division-6.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.