DETBA Value and Hexanal Production with the Combination of Unsaturated Fatty Acids and Extracts Prepared from Soybean Seeds Lacking Two or Three Lipoxygenase Isozymes

Abstract

Hydroperoxide and n-hexanal production by lipoxygenase action is an important problem in the effective use of soybean seeds for food ingredients. We examined here the additional effect of unsaturated fatty acids on the 1,3-diethyl-2-thiobarbituric acid (DETBA) value (index for hydroperoxide production) and n-hexanal production with two normal soybean cultivars; three mutants partially lacking lipoxygenase and containing only L-1, L-2, or L-3; and one mutant completely lacking lipoxygenase (L0). Among the soybeans tested, the L0 soybean had the lowest levels of both DETBA value and n-hexanal production. The low DETBA values were maintained over a wide range of pH (4−10) and temperature (4−70 °C) and were not influenced by the addition of unsaturated fatty acids. These results suggest that the L0 soybean could be an excellent soybean source for making soybean products with a combination of soybean and other food ingredients. Keywords: Soybean; lipoxygenase isozymes; hexanal; DETBA value; lipid peroxidation; unsaturated fatty acid; food ingredient; Glycine max