ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
SUMMARY– The principal tannin of sorghum is a leuco-anthocyanin yielding luteolinidin (3′,4′,5,7-tetrahydroxy-flavylium) when heated with mineral acid. The precursor, luteoforol, has most of the properties of 3′,4,4′,5,7-penta-hydroxyflavan prepared by reduction of eriodictyol. Luteoforol, when treated with concentrated mineral acid in the cold, gives a purple color with Λmax550nm. A method for the determination of luteoforol in sorghum, based on this property, is described. The results with a number of varieties of sorghum are compared with those obtained by the AOAC Folin-Denis method. The contribution of luteoforol to the “tannin” so determined varies from 1 to 〈 25%. Except for one sample of Kaffir corn, which contained leucocyanidin as well as luteoforol, no other tannins were detected. The “tannin” content varied widely, (from 0.05 to 0.67% as tannic acid), a white-skinned variety having the least. The uniformity of commercial samples can be rapidly evaluated by single-grain determinations of luteoforol.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1969.tb00919.x
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