INTERFERENCE OF PHYTIC ACID WITH EXTRACTION OF PROTEINS FROM GRAIN LEGUMES AND WHEAT WITH ACETIC-ACID

Formation of insoluble phytic acid-protein complexes in different legumes and various cultivars of wheat under acidic pH were compared by Kjeldahl nitrogen and aluminum lactate polyacrylamide gel electrophoresis (AL-PAGE). Seed proteins extracted in 5 M acetic acid (HAc) were treated with various concentrations of phytic acid solution. The most precipitation occurred in faba beans and the least in wheat. Among legumes, field bean showed very little precipitation with phytic acid. Slow-moving (in AL-PAGE) HAc soluble proteins of the legumes were found to be more sensitive to form insoluble complexes with phytic acid compared with those of medium mobility. Recovery (solubilization) of the bound proteins from their insoluble complexes by NaOH treatment varied selectively, however, the stability of these proteins remained unaffected during the recovery process. Among various cultivars of wheat more of the low-mobility proteins were recovered for cvs. Fielder, HY 320, and Norstar, whereas in the case of Katepwa and Glenlea more of the fast-moving bands were recovered by NaOH treatment.