The production of refined konnyaku ( Amorphophallus konjiac ) sol (1) Aimed at promoting the utilization of konnyaku powder sol, we developed a mannan washing apparatus equipped with the ultrasonication treatment system that allows the refinement of the powder on an industrial scale. Then, we attempted to determine the optimum conditions for its refinement and to improve the powder's sol quality, using the apparatus. Regarding the optimum conditions for the refinement of konnyaku powder sol, it was found that the ethanol concentration of 30% and the refinement temperature of 30°C were critical and the treatment by ultrasonication twice, for 10 min and 5 min was most effective for the treatment. The konnyaku powder sol produced by the method with ultrasonication treatment showed a higher degree of whiteness than that produced without ultrasonication treatment. Furthermore, the levels of undesirable odors from the sol were markedly reduced and the appearance, viscosity and dietary fiber content were superior in the former product with ultrasonication. In addition the sensory evaluation quality of the sol was higher in the product prepared by using ultrasonication. It was thus demonstrated that the quality of konnyaku powder sol was improved using the newly developed apparatus. (2) Soba (buckwheat) noodles were made from soba flour with konnyaku powder sol added as a binder. The results showed that the best product was obtained using soba flour containing 2% konnyaku powder. The addition of konnyaku powder was thus recognized to improve the quality of the soba noodles. The use of the wastes such as the coat and the eluate of adzuki bean seed: (1) This study was performed in order to make good use of seed-coat powder that was dried and milled (Material A), and the eluate from adzuki bean seeds (Material a), a by-product of adzuki bean jam. The reaction conditions of 40°C and the duration of 15 min (Material B) or 10 min (Material b) were found to be optimal for the ultrasonication of seed-coat powder and the eluate from adzuki bean seed. The odor decreased and the hue of adzuki beans of Material B and Material b increased by the refinement with ultrasonication. Comparatively large amounts of components such as protein, dietary fiber and minerals were contained in this Material B. Material B also showed a strong anti-oxidative activity. (2) The usage of adzuki beans as a food material was tested by preparing muffin, steamed sponge cake and cookies, and their physical properties, palatability and preservation were studied. Material B could be substituted for flour by up 20% in muffin, steamed sponge cake or cookies without any effect on their physical properties and palatability. Moreover, whole adzuki bean powder showed similar favorable results. Sample B (adzuki bean jelly with Material b) showed the hue of adzuki beans, low odor, and was favored more than sample S (control) or sample A (adzuki bean jelly with Material a). The 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and total polyphenol content of sample B and sample A were higher than those of sample S. Further addition of konnyaku sol at 2.4% to the adzuki bean jelly made it harder in texture and lower in syneresis. Observation of the tissue by cryo-scanning electron microscopy showed percolation of the konnyaku sol into the agar network of sample B. Ultrasonication was proved to be promising for the improvement of the quality of the seed-coat powder, the eluate from adzuki bean seeds, and whole adzuki bean powder.