HEXANAL ACCUMULATION AND DETBA VALUE IN HOMOGENATE OF SOYBEAN SEEDS LACKING 2 OR 3 LIPOXYGENASE ISOZYMES

Soybean lipoxygenases are responsible for the generation of undesirabl e flavors which limit wide utilization of soybeans in food products. L ipoxygenase-lacking mutants are expected to be soybeans with improved flavors. In this study, the accumulation of hexanal and the 1,3-diethy l-2-thiobarbituric acid (DETBA) value in homogenates were determined f rom two normal soybean cultivars (L(123(S)) and L(123(F)), three soybe an cultivars with L-1 (L(1)), L-2 (L(2)), and L-3 (L(3)), and one soyb ean cultivar lacking all three lipoxygenase isozymes (L(0)). Hexanal a ccumulation in the homogenates was in the order L(2) > L(123(S)) > L(1 23(F)) > L(1) > L(3) > L(0). The DETBA value in the homogenates was in order L(123(S)), L(123(F)) > L(2), L(3) > L(1), L(0). Such cultivar d ifferences were induced after the soaked soybeans were ground or after the soybean flour was wetted. These results suggested that L(0) could become a superior soybean for food ingredients, concerning flavors or iginating from lipoxygenases.