Interaction of chickpea (Cicer arietinum L.) legumin with oxidized linoleic acid

Chickpea legumin has been purified and incubated under oxidizing conditions with linoleic acid to investigate the influence of this acid on the struct ure and nutritional quality of the protein. At the end of the incubation ti me, >30% of the linoleic acid was oxidized. The oxidized linoleic acid was highly detrimental to legumin, and the electrophoretic pattern of the prote in was completely changed after the incubation period. Nevertheless, neithe r polymerization nor cleavage of the protein was observed as deduced from g el filtration chromatography, suggesting that the changes observed in nativ e electrophoresis were probably due to oxidation of legumin. The incubation of legumin with linoleic acid also produced a diminution of the contents o f methionine and histidine, by 81.3 and 24.3%, respectively. Finally, in vi tro protein digestibility of chickpea legumin was also seriously affected b y the incubation with linoleic acid, decreasing from 84.1 to 69.2%.