This study was performed to examine the effects of dietary dried bonito protein hydrolysate (KH) on the glucose tolerance and lipid metabolism of Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a type 2 diabetes model. 11-week-old male OLETF and Long-Evans Tokushima Otsuka (LETO) rats as the negative control were given either 5% KH diet or AIN76 standard diet (as control diet) for 22 weeks. The amount of food intake of the OLETF group increased compared with that of the LETO group, but the body weight gain of the OLETF-KH group was suppressed significantly (p<0.05) compared with that of the OLETF-C group (as positive control). The retroperitoneal fat weight of the OLETF group showed a markedly larger amount increase much more than that of the LETO group, but that of the OLETF-KH group showed a smaller amount of increase than that of the OLETF-C group. The serum glucose, insulin, triglyceride, total cholesterol, LDL cholesterol levels of the OLETF-KH group were significantly lower (p<0.05) than those of the OLETF-C group. Further more, in the oral glucose tolerance test, the postprandial blood glucose level of the OLETF-KH group was suppressed significantly (p<0.05) compared with that of the OLETF-C group. These results suggest that KH is the functional food source that can suppress body fat level and improve the glucose tolerance of animals.

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In an attempt to develop a new way of utilizing discolored laver, we determined whether laver is useful for γ-aminobutyric acid (GABA) production. GABA has been shown to suppress hypertension in clinical practice. Lactobatillus brevis NBRC 12005 producing GABA grew in our laver suspension, and 2. 3 mM GABA was produced from 2. 5 mM glutamic acid in laver, suggesting that laver is a useful substrate for lactic acid fermentation by GABA-producing bacteria. The dry products of unfermented laver, fermented laver and fermented laver with glutamate were added to diet at 1 %, and given to spontaneously hypertensive rats (SHR) for 7 weeks. It was found that fermented laver suppresses hypertension.

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Low-temperature storage has been considered as a good storage method for preserving the quality of grains. In this study, the equilibrium moisture contents of buckwheat in both adsorption and desorption processes were determined at storage temperatures of 5, 15 and 25°C. The Chen-Clayton equation was applied to the observed data. It was found that the calculated values were in good agreement with the observed data. The calculation results of the moisture content levels of buckwheat were counter plotted with temperature and water activity in both adsorption and desorption processes. It was found that the water activity of buckwheat at a moisture content of 15 (%, wet basis) and at 15°C was less than 0.66. From these results, low-temperature storage at about 15°C was shown to be an effective method for prevention of fungi from the microbial point of view.

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We investigated opening and threshing technique for fresh and frozen scallop (Patinopecten yessoensis) shells using saturated and superheated steam. The experiment was carried out at normal pressure and under pressure. The pressurization condition was useful for threshing the molluscous body from the shell. In particular, superheated steam under pressure was useful for opening and threshing frozen shells. The ligament of scallops threshed with superheated steam was frozen. It was found that there was no significant thermal denaturation on the surface of adductor muscle in the frozen specimens. It was suggested that the adductor muscle of scallops even with heat treatment during opening and threshing of frozen shells is suitable to be eaten raw.

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