[in Japanese]

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Quantitative difference of the 7S globulin subunits in immature seeds of five vegetable-type (Edamame) and three grain-type cultivars of soybean which were harvested 35 days after flowering were examined by sodium dodecylsulfate-polyacrylamide electrophoresis (SDS-PAGE). In the vegetable type soybean cultivars, both the immature and mature seeds of Shirayama-dadacha and Kanro in which the seeds are shriveled and brown color in feature, showed reduced levels of β-conglycinin β-subunits and sucrose binding proteins. Densitometric scans of SDS-PAGE protein gels from vegetable-type cultivar, Shirayama-dadacha, confirmed that levels of β-conglycinin-β-subunits and sucrose binding proteins were about 70 and 75%, respectively, in comparison with those of grain-type cultivars. These quantitatively reduced levels of 7S globulin leaded to be possible increase of 11S/7S ratio and then be preferable for nutrition value. By two-dimensional gel electrophoresis, the different patterns of β-conglycinin β-subunits were found in vegetable-type cultivars, Shirayama-dadacha and Kanro, compared with those of grain type ones. The protein spots that showed different patterns or expressed reduced levels were examined by amino acid sequence analysis. These protein spots were identified as β-conglycinin β-subunits and sucrose binding proteins.

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We compared the behavior of five kinds of coagulants on gelation of soybean proteins on the basis of breaking stress of Tofu (soybean curd) prepared by using different amounts of coagulant obtained by puncture and compression tests. The acid-type coagulant such as glucono-δ-lactone (GDL) or L-ascorbic acid (LAA) requires a lower concentration, as compared with the salt-type coagulant such as calcium sulfate (CaSO₄), Magnesium chloride (MgCl₂), or a bittern, to form a Tofu gel of the largest breaking stress, beyond this concentration the gel was rapidly disaggregated. On the contrary, the maximum breaking stress of Tofu prepared by salt-type coagulant, CaSO₄, MgCl₂, or bittern, slightly decreases with increasing coagulant concentration over a wide range. The behavior of CaCl₂ on heated soybean milk is intermediated between those of acid-type and another salt-type coagulants even though CaCl₂ belongs to a class of salt-type one. Based on the observations from the coagulability and texture of Tofu gel formed, the most suitable concentration, above which the poor taste develops, for each coagulant was determined. When the GDL-MgCl₂ mixtures were used as a coagulant, the behaviors of them were divided into three types depending on the range of compositions. The mixed coagulants of the composition between 0.18 and 0.37 mole fraction of MgCl₂ showed a synergistic effect of mixing acid-type coagulant with salt-type one, and the behaviors of which composed of either below 0.18 or over 0.37 mole fraction of MgCl₂ were identical with those of the individual coagulant, GDL or MgCl₂, respectively.

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The effect of sulfides which were produced by cutting or grinding of the Allium vegetables on the browning of apple slices was studied. The fresh apple slices did not turn brownish when the apple slices were packed with 10 μl dimethyltrisulfide in 500 ml polypropylene bag. Moreover, browned apple slices were turned white by dimethyltrisulfide. It was found that methanethiol was formed when apple slice was packed together with dimethyltrisulfide and the browning of apple slice was suppressed by methanethiol. In case of dimethyldisulfide, the co-packaging with the slice resulted in a gradual formation of methanethiol, the browning was moderately suppressed. On the other hand, dimethylmonosulfide did not suppress the browning, and co-packaging the slice with dimethylmonosulfide resulted in no formation of methanethiol. These results indicate that most effect of browning control by trisulfide and disulfide is due to methanethiol formed by an interaction of these sulfides and apple slice, and that monosulfide can not become a substrate of methanethiol formation.

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Smoke flavor were extracted from wood vinegar prepared from driftwood by using hexane, diethyl ether, and hexane — ether mixture, respectively. In addition, mutagenicity test was conducted against Escherichia coli WP2 uvrA, Salmonella typhimurium TA100, TA98, TA1535, and TA1537. The hexane extract and hexane — ether mixture extract didn't contain organic acids, formaldehyde, methanol, and contained mainly phenols. The diethyl ether extract contained organic acids, furans, ketones, phenols, formaldehyde and methanol. As a result of the mutagenicity test, the hexane — ether mixture extract didn't show an increase in the number of revertant colonies against any of the bacteria.

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This study is attempted preparation of fermented goat milk products containing probiotic lactic acid bacteria (Lactobacillus acidophilus JCM11047) derived from human intestine, by the assistance of a yogurt starter, Streptococcus thermophilus 510 strain.
The corresponding growth rates of the two strains in goat milk were better than in cow milk. This is believed to be due in part to the higher content of non-protein nitrogen in goat milk.
The co-culture with the S. thermophilus 510 strain promoted the growth of the JCM11047 strain. The viable cell count of the JCM11047 strain in the resulting product stored at 4°C gradually decreased from the order of 10⁸ cfu/ml to 10⁷ cfu/ml over 7 days. These results indicate a possible method for the production of probiotic fermented goat milk using L. acidophilus.

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The effect of the antler-shaped fruiting body of Ganoderma lucidum (Rokkaku-Reishi, RR), which has been used as a traditional supplement for human health, on the high-fat diet-induced hyperlipidemia was investigated in Syrian hamsters. RR was administered to the hamsters by adding the dried and powdered fruiting body to the high-fat diet at doses of 0.1 and 1.0% (w/w). One week later, non-fasting plasma samples were collected and the levels of triglyceride (TG) were determined. The results were as follows : hypertriglyceridemia was induced by the high-fat diet and the elevated TG was significantly suppressed by the RR administration in a dose-dependent manner. Fasting plasma TG at 2 weeks after the administration was also significantly decreased in the RR-administered hamsters. These findings suggest that RR possesses hypotriglyceridemic effect.

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We investigated the tolerance of L. plantarum HOKKAIDO against simulated digestive juice in vitro and a potential of the soybean milk yoghurt produced with this bacteria for synbiotics. The viable cell count decreased approximately 10⁴-fold over 4 h in the gastric juice (pH 2.5) that contained 0.04% pepsin but remained at the initial level in it at pH 3.0. HOKKAIDO cells were not killed in the presence of 0.4% bile powder, but rather proliferated as in the absence of the powder. Soybean milk fermented using HOKKAIDO cells gave yoghurt-like food. The amount of lactic acid, pH and lactic acid bacterial count in the food were measured and these data indicated that HOKKAIDO was a good fermenter for soybean milk. Moreover, the fermented food contained the initial amount of raffinose-series oligosaccharides that proliferate Bifidobacteria. Taken together, we consider that the soybean milk yoghurt functions as synbiotics.

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