Abstract
In order to evaluate the effect of lipoxygenase (LOX) on the sensory taste of tofu, relationships between the contents of several components (protein, total lipids, free sugars, isoflavones, total carbonyl compounds and hexanal) and the sensory taste of tofu made from normal or LOXs-deficient soybean cultivars were investigated. The tofu made from Suzuyutaka (normal cultivar) tasted sweeter and more mouthful (rich) compared with those from LOX-2, 3-deficient Yumeyutaka and LOX-1, 2, 3-deficient Ichihime. No difference in the degree of undesirable taste could be detected among the tofus made from the three soybean cultivars by panel. The three different tofus were similar in their contents of protein, total lipids, free sugars (sucrose, stachyose, raffinose, glucose) and isoflavones. The total carbonyl compounds and hexanal contents in the tofu of normal soybean Suzuyutaka were much more than those of LOXs-deficient soybeans (Yumeyutaka and Ichihime). These results suggest that oxidation products of unsaturated fatty acids by LOX contribute to the mouthfulness (richness) for the taste of tofu, and strengthen sweetness in the presence of free sugars by contrast effect.
