Components Responsible for the Undesirable Taste of Soybean Seeds

The components responsible for undesirable taste in soybeans have been investigated and intensities of undesirable taste were measured by electrophysiological methods. Bitterness and astringency in soybeans were shown to be caused by soybean glycosides such as saponins and isoflavones, and the soybean sapponin A group contributes most strongly to the undesirable taste. In the three electrophysiological methods to measure intensity of undesirable tastes, soybean saponins did not induce the membrane potential change of neuroblastoma cells (N-18 clone) and the electrical response of the chorda tympany nerve of rats, and only the electrical response of the glossopharyngeal nerve of the frog was induced by soybean saponins. These results showed that the mechanism of the undesirable tastes caused by soybean saponins was likely to be different from those of basic tastes (sweet, salty, sour, and bitter).