In this study, we investigated the effects of the electric pretreatment of garbage on biogas (methane) production. Both the garbage atomization, and garbage solubilization were enhanced by pretreatment with 30 V of direct electric current. Moreover, the number of contaminants attached to the surface of garbage components was decreased by electric pretreatment. Furthermore, garbage pretreatment with direct electric current enhances biogas (methane) fermentation.

　We investigated the deodorizing effects of hot-water extracts of samples of 26 species of wild grasses native to Hikone City, Shiga Prefecture against methanethiol (CH₃SH), and compared them with the deodorizing effects of methanol extracts of the samples. The deodorizing activities were determined from the amounts of CH₃SH remaining using headspace gas chromatography. Each of the 5.0mg hot-water extracts and methanol extracts was added to CH₃SH and then examined. As a result, deodorizing effects stronger than those of green tea were observed in hot-water extracts of samples of 12 species and methanol extracts of samples of 11 species. Furthermore, deodorizing activities of 100% were found in eight species. Among them, the deodorant active substances of Glechoma hederacea [2], Artemisia capillaries [3], Porentilla fragarioides [4], Gnaphalium affine [5], Stenactis annuus [6], and Oenothera biennis [8] were more effectively extracted by hot-water extraction than methanol extraction. These substantial deodorizing effects of hot-water extracts of wild grasses have not been reported to data. This experiment suggests that substances originating from plants are promising for possible deodorant applications.

　Polyphenol oxidase (o-diphenol: oxygen oxidoreductase, EC 1.10.3.1, PPO) in Japanese butterbur was purified about～151-fold with a recovery rate of 11.3% by acetone fractionation, ion exchange chromatography, hydrophobic chromatography, and gel filtration. The purified enzyme appeared as a single band on PAGE and SDS-PAGE. The molecular weight of the enzyme was estimated to be about 26,000 and 25,000 by gel filtration and SDS-PAGE, respectively. The purified enzyme quickly oxidized chlorogenic acid and (－) -epicatechin. The Km values of the enzyme were 0.14 mM for chlorogenic acid (pH 5_.0, 30℃) and 0.7 mM for (－) -epicatechin (pH 8.0, 30℃). The optimum pHs were 5.0 and 8.0 for chlorogenic acid oxidizing (ChO) and (－) -epicatechin oxidizing (EpO) activities, respectively. In the pH range from 4.0 to 9.0, both ChO and EpO activities were stable at 4℃ for 22 h. The optimum temperature of both activities was found at 30℃. Both activities were 50%-inactivated after heat treatment at 60℃ for 10 min. Both activities were strongly inhibited by _L-ascorbic acid and _L-cysteine at 5 mM

　Sudachi (Citrus sudachi hort. ex. Shirai) fruit is a kind of acid citrus. It rapidly degreens at room temperature. Ethanol treatment retards ripening and senescence of harvested horticultural products. We investigated the effects of postharvest ethanol vapor treatment with ethanol pads on the quality of sudachi fruit to prolong the storage period. Mature green sudachi fruit were packed in a perforated polyethylene bag without (control) or with a 0.3, 0.6, 1, 3 or 6 g ethanol pad as the ethanol vapor treatment and stored at 20℃ in darkness. The chlorophyll contents of fruit treated with a 1 g ethanol pad decreased more slowly than those of the control fruit, accompanying suppression of loss of fresh weight. There were no significant differences in the internal quality between the control and ethanol vapor-treated fruit, including total soluble solids (TSS) , titrable acidity (TA), TSS / TA ratio, pH, L-ascorbic acid content, and L-dehydroascorbic acid content in the pulp juice. However, peel browning of fruit treated with 3 and 6 g ethanol pads occurred. From these results, it is demonstrated that ethanol vapor treatment of sudachi fruit could retard degreening and suggest the possibility that treatment could prolong the storage period without negative impacts on internal quality.

　Nuts are rich in vegetable proteins and lipids, and can be easily made into a milk-like emulsion such as coconut milk or hemp milk. In this study we attempted to produce a cheese-like food from various nuts instead of from cows’ milk. First, we investigated the curdling activity of various proteases on emulsions made individually from 13 species of nuts. The proteases bromelain, papain, subtilisin, thermolysin and a protease from E. faecalis could curdle the milk-like emulsion made from 12 species of nuts. The emulsions made from hemp nuts, coconuts, almonds, pine nuts and macadamia nuts curdled especially well. We then successfully produced cheese-like foods from 6 species of nuts (hemp nuts, coconuts, almonds, pine nuts, cashew nuts and macadamia nuts). Compared to cheese made from cows’ milk these nut-cheeses were softer, the curd yield from the emulsion was almost the same, the protein content was lower and the lipid content was higher. Hemp nut cheese was the most similar to cows’ milk-cheese in its composition and gave the highest yield of cheese among all of the tested nuts.