Observation of Soybean Foods under Electron Microscope

Abstract

Of the electron microscopic pictures taken in the investigation on protein bodies and the protein in soybean seeds, some were presented to elucidate fine structures of them and their changes in processing. No change in protein bodies and spherosomes in intact cells of soybean cotyledon occurred by soaking in water overnight, while remarkable changes, such as bursting of protein bodies, curdling of their protein in mass without dissolving, and converting of spherosomes into rather large oil droplets, were observed after successive heat-steaming and fermentation with Bacillus natto. In tofu gel, a network is formed with protein microgranules, and oil droplets located in groups along it. The meshy structure of fresh tofu for kori-tofu is denser than that of ordinary tofu. During freezing, protein microgranules are localized and denatured by growth of ice crystals.