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Effect of processing on the antinutrient content of rapeseed
Author(s) -
Fenwick G. Roger,
Spinks E. Ann,
Wilkinson Andrew P.,
Heaney Robert K.,
Legoy Maurice A.
Publication year - 1986
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740370805
Subject(s) - glucosinolate , antinutrient , rapeseed , chemistry , food science , tannin , extrusion , meal , myrosinase , hydrolysis , phytic acid , agronomy , biochemistry , brassica , biology , materials science , metallurgy
The effects of dry extrusion of mixtures of rapeseed and soya bean on total and individual glucosinolates, selected glucosinolate hydrolysis products, myrosinase, sinapine and tannins have been compared with those of more conventional processing, e.g. lime treatment, micronisation and ammoniation. Extrusion at 150°C effectively inactivated myrosinase but had relatively little effect on glucosinolate content unless chemicals were added before extrusion; the most effective combination, 5% alkali+1% ferrous sulphate, reduced the total glucosinolate content by 80%. Under the latter conditions very high (>30 μmol g −1 defatted meal) levels of nitriles were produced, leading to the suggestion that nitriles in addition to oxazolidine‐2‐thione and isothiocyanates be used to monitor the effectiveness of processing techniques. None of the extrusion conditions showed any significant effect on reducing sinapine or tannin contents. In view of the chemical data presented, and the probable adverse effects which the processing conditions selected have on the nutritional value of the processed meal it seems unlikely that extrusion will play a significant role in rapeseed detoxification.