ISO 9648:1988 pdf download. Sorghum — Determination of tannin content.
ISO 9648:1988 specifies a universal method for the determination of tannin content in sorghum grains.
It is not specific for one single type of polyphenols. Its usefulness. meanwhile, is justified by the good negative correlation observed between the metabolizable energy of sorghum grain, measured using animal experiments on cocks, and the results obtained using this method.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encour aged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards.
IS0 712: 1985, Cereals and cereals products – Determination of moisture content (Routine reference method).
ISO 950: 1979, Cereals- Sampling (as grain).
6 Sampling
Sampling shall be carried out in accordance with ISO 950.
Sorghum grains intended for determination of the tannin con tent may be conserved for several months, protected from the light, and should preferably be dried.
7 Preparation of the test sample
Remove any extraneous matter other than sorghum from the laboratory sample and crush the sample in the mechanical crusher (5.1) so as to reduce it to particles of a size which will pass completely through the sieve (5.2).Mix thoroughly.
The tannins in crushed products oxidize rapidly and therefore it is recommended to proceed immediately with the analysis after crushing.
NOTE -The crushed product may be conserved at most for several days, protected from the light, and should preferably be dried.ISO 9648:1988 pdf download.