To elucidate a mechanism of the inhibitory action of acetic acid on respiration in yeast, Debaryomyces hansenii, transport of acetic acid into cells and effects of acetic acid on enzymes in a TCA cycle were investigated. (1) D. hansenii cells grown in the medium containing 0.2M of acetic acid, intracellular concentration of acetic acid increased to about 20-fold over that of the cells suspended in the absence of acetic acid. This result indicated that acetic acid in the medium was transported into cells, resulting in accumulation of acetic acid in cells in a large quantity. (2) On the cells grown in medium containing 0.33M of acetic acid, concentration of all organic acids in a TCA cycle decreased compared with that of the cells grown in the absence of acetic acid in cells and media. (3) Among the TCA cycle enzymes 2-oxoglutarate dehydrogenase complex and pyruvate dehydrogenase complex (PDHC) were found to be severely inhibited by 200mM acetic acid, and PDHC was inhibited completely even by 0.2mM acetic acid. These results suggested that PDHC primarily inhibited by acetic acid accumulating in cells, resulting in the decrease in organic acids in a TCA cycle and the growth inhibition.

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Soybean dietary fiber consists of many kinds of polysaccharides which have different physiological effects on human, and its physiological function may be changed by heating. In this paper, the composition of polysaccharides in cell wall and its changes by heating were described. High yield of crude polysaccharides was observed in roasted soybean, suggesting that high molecular weight compounds were produced by heating. On the other hand, as an increase of soluble hemicellulose and a decrease of insoluble hemicellulose were observed, low molecular weight compounds may be produced by heating. And also we found some differences in ion-adsorbing ability between raw and roasted soybean. Adsorption ability of aluminium ion by raw soybean soluble dietary fiber (SDF) was most remarkable. Adsorption of aluminium by pectic substance-1 and 2 (hot water extract and 0.5% ammonium oxalate extract) and hemicellulose-1 (1N-sodium hydroxide extract) isolated from peeled soybean was observed. But pectic substance-1 and 2 isolated from soybean peel had lower adsorption ability than peeled soybean. All of those adsorption abilities were decreased by heating. Hemicellulose-2 (4N-potassium hydroxide extract) and cellulose isolated from soybean had almost no adsorption ability.

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Physical properties correlated to eating quality of seven rices cooked in different cooking conditions were measured and analysed. Measurements were carried out with Tensipresser Boy using the four point mensuration method of modified two bite system which was developed based on the principle of a continuous minute deformation method of the multi-biting test already reported. Thailand rice (typical indica type), when cooked at optimum added water level by increasing pressure microwave cooking, became soft mouthfeel cooked rice resemble to japonica type rice. Japonica type rice cultured in China, California (USA) and Australia, when cooked at optimum added water level by increasing pressure microwave cooking, became also soft mouthfeel cooked rice closely resemble to japonica type rice cultured in Japan. Ratio of work load of a plunger at 2nd bite to that at 1st bite was useful to compare the mouthfeel of cooked rice of various kinds under different cooking conditions. Parameters for 40% and 80% deformation of cooked rice were useful to estimate the difference in physical properties between external and internal layers of cooked rice kernels. When balance values of seven rices cooked in different cooking conditions were measured by this method, they also varied with cooking conditions of rices. Thailand rice mixed half and half by glutinous and non-glutinous rice and cooked in optimum cooking conditions exhibited good eating quality equal to japonica type rice cultured in Japan. Balance values of this cooked rice calculated from those of original rices closely resemble to those of japonica rices. This new measuring method clearly indicated numerical changes in physical properties of rices cooked in different cooking conditions during standing time on japonica type rice cultured in China.

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In order to extend its utility for food additives, the water-solubilization and stabilization of lycopene were examined. The solubilization was undertaken using surface active agents or cyclodextrin (CD). An orange emulsion was obtained by mixing 0.1% lycopene in oil phase with arabic gum, dextrin and glycerol followed by emulsification in water. Lycopene-CD complexes were prepared by kneading the mixture of lycopene and CD with a little of water. The complexes were soluble in water, and the aqueous solutions were red. Out of all the complexes of α-, β-and γ-CD with lycopene, the complex with γ-CD was found to be most stable. The inclusion rate became 100% when the molar ratio of lycopene to γ-CD was 1:200. The stability of lycopene in aqueous solution of CD inclusion complexes was improved by the addition of gluten or ascorbic acid and the effect of gluten was better.

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Tyrosine degradable activity by lactic acid bacteria was examined using tyrosine as a substrate by stationary culture. The activity was assayed by measuring the decrease in tyrosine in the medium by photodiode array detection in HPLC. Seven strains of lactic acid bacteria which converted tyrosine into tyramine during cultivation were selected from 35 strains of type culture. High activity was observed in Enterococcus sp. and Lactococcus lactis subsp. cremoris, which degraded more than half of tyrosine added in a concentration of 1% (w/v) in three days of cultivation. In the reaction system using growing cells, Enterococcus faecalis IFO 3971 and Lactococcus lactis subsp. cremoris which showed the highest activity degraded tyrosine and solubilized white particles composed mainly of tyrosine in bamboo shoots cooked by hot water. After the reaction lactic acid and acetic acid content increased considerably whereas sugar content decreased.

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The volatile concentrates of bamboo shoots were prepared by the adsorption method of head space vapor (HSV) using Tenax^re04 TA trap and by solvent extraction. The volatile concentrates prepared by adsorption of HSV had a light and fresh aroma. On the contrary volatiles prepared by extraction method had a heavy and rich aroma. Each of the concentrates was analyzed by gas chromatography and gas chromatography-mass spectrometry. As the volatiles, 23 components in raw bamboo shoots and 31 components in boiled bamboo shoots were identified by HSV method. The major components in raw bamboo shoots were aldehydes such as hexanal and (E)-2-hexenal, and aromatic hydrocarbons such as toluene, ethylbenzene and xylene. The major components in boiled bamboo shoots were dimethyl sulfide, 3-methylfuran and acetone. Seventy components in raw bamboo shoots, 60 components in boiled bamboo shoots were identified by extraction method. Saturated fatty acids, saturated hydrocarbons and aromatic compounds with high boiling point which were not found in HSV were found in extracts as common components. Hexanal, hexanol, methyl salicylate and benzyl salicylate which were major components in raw sample were decreased in boiled sample. Whereas vanillin, benzyl alcohol and benzyl cyanide were increased. It was suggested that these aromatic compounds might contribute to the sweet and characteristic aroma of boiled bamboo shoots.

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To elucidate the mechanism of softening of dried kelp Laminaria sp. by seasonings during processing, calcium release from calcium alginate (Ca-Alg) immersed in organic acid, sodium chloride, amino acid and sugar solutions was examined. Regardless of the kind and concentration of seasonings, calcium release from Ca-Alg reached equilibrium within a few minutes after immersion. Organic acids, sodium chloride and monosodium glutamate resulted in a rapid increase below 0.2M and a slight increase to 1M in the rate of calcium release, followed by leveling off. Glycine as well as alanine, showed a gradual increase from 0.2M to 1M in the rate of calcium release followed by a rapid increase at concentrations higher than 1M. A rise in immersion temperature increased the rate of calcium release with increasing in concentration. The effects of seasonings on the rate of calcium release with increasing in concentration. The effects of seasonings on the rate of calcium release were in the order of tartaric acid_??_citric acid>malic acid>lactic acid>monosodium glutamate>succinic acid_??_sodium chloride>acetic acid>alanine>glycine_??_sucrose. Ion exchange selectivity coefficient for exchanging Ca²⁺ for H⁺ was proportional to the dissociation constants of organic acids at low concentrations. In the case of sodium salt, the selectivity coefficient for exchanging Ca²⁺ for Na⁺ of monosodium glutamate was considerably larger than that of sodium chloride. These results clearly show the type of seasonings, concentration and temperature which are most effective for release of calcium from Ca-Alg.

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A bioassay procedure of tomatine was examined with animal cell cultures. To detect tomatine, cytotoxicity assay procedures were applied. Cell lines of HepG 2, HuH 6KK and NIH 3T 3 were suitable for this purpose, but those of HL 60 and U 937 were not. As cytotoxicity detection procedure, alamar blue reduction, chemiluminescence, MTT reduction, WST-1 reduction and others were examined. The combination of HepG 2 cell and chemiluminescence method was more suitable for detecting tomatine than any other ones. It took for 75min to detect tomatine, and the detection limit was 2.5mg/kg fresh weight. From unripe tomato, 353mg/kg of tomatine was detected. From ripe tomato, 5.42mg/kg of tomatine was detected. Tomatine content decreased as tomato fruit became ripe. Wild type tomatoes such as L. hirsutum and L. peruvianum showed high tomatine contents. Tomatoes and tomato products on the market showed low tomatine contents. A tomato, introduced tobacco mosaic virus resistant factor with genetic engineering, was planted and its tomatine contents was determined. The tomatine content of the recombinant tomato was the same level as that of its host tomato.

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To elucidate the mechanism of softening of combu fronds by seasonings during cooking process, changes in some properties of cell-wall constituents of combu cooked in model solutions of water, 1% lactic acid, 5% sodium chloride and 10% sucrose were examined. The cooked sample was fractionated to pretreated material (PM), water insoluble fraction (WIF), alkali insoluble fraction (AIF) and a-cellulose fraction by the method of CRONSHAW et al. The weight ratio of WIF in lactic acid-and sodium chloride-treated samples to the weight of PM of each sample was smaller than that of waterand sucrose-treated samples. However, the weight ratio of AIF and the a-cellulose fraction to the weight of PM was greater than that of water-and sucrose-treated samples. The water holding capacity of the PM, WIF and a-cellulose fraction in the lactic acid-treated sample was smaller than that of water-, sodium chloride- and sucrose-treated samples. The water holding capacity of the PM and WIF in the sodium chloride-treated sample was greater than that of the water-treared sample, but that of the a-cellulose fraction was smaller than that of the water-treated sample as well as the lactic acid-treated sample. a-Cellulose fraction of each samples showed the same X-ray diffraction pattern as typical crystalline cellulose. Solubility in Cadoxen and susceptibility to cellulase hydrolysis of the a-cellulose fraction of lactic acid- and sodium chloride-treated samples were greater than those of water- and sucrose-treated samples.

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Water absorption properties of soybean under different hydrostatic pressures and temperatures of water were investigated for three kinds of soybeans (Japan, China, and U.S.A). Japanese soybeans showed the highest equilibrium moisture content among the three. Quantity of water absorption, m was represented by the modified diffusion equation, that is m=(e^kl-1)/(e^kl+α), where k, α and t were water absorption rate constant, absorption resistance constant and absorption time, respectively. Further, k and α were given by the following equations. where, ΔE, T, P, ΔE' and R_g were apparent activation energy, absolute temperature, hydrostatic pressure, correction factor and the gas constant, and A', A, B, C, and D were constants. The apparent activation energies were 4.7 (Japan), 4.2 (China) and 4.8 (U.S.A) kJ/mol, respectively.

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The vapor pressure, density and kinematic viscosity of dry milk solutions of concentrations between 6% and 40% (w/w) were measured at temperatures between 0-60°C. The vapor pressure measured by a static method was correlated to temperature by using the Clapeyron's equation (low concentration) or the Antoine's equation (high concentration). The viscosity of solution calculated from its kinematic viscosity and density was correlated to temperature by using the Andrade's equation. Since the temperature dependence on vapor pressure was similar in its form to that on viscosity, the vapor pressure of the dry milk solution could be directly correlated to its viscosity.

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Zein, water insoluble corn prolamin, can be transformed to the transparent, flexible and waterproof film by dissolving into the hydrate organic solvents such as ethyl alcohol and acetone and then drying. However, the resulting film prepared from aqueous ethanol did not show enough waterproof property, compared with the film from aqueous acetone. The behaviour of zein in both solvents and the properties of the resulting films were examined to find possible reasons for their different properties using the following methods; a particle distribution with laser scattering method, fourier transformation scanning electron microscope, fourier transformation nuclear magnetic resonance, infrared absorption spectroscopy and small angle X-ray scattering (SAXS). SAXS revealed that zein molecule in the film from aqueous acetone had more regular arrangement than that from aqueous ethanol. In addition, zein molecule in aqueous acetone relative quickly formed the basic small aggregates and grew into the huge aggregates, forming the film structure faster than in aqueous ethanol. According to the analysis using FT-NMR, the growing aggregate from acetone was likely to expose their hydrophobic regions outside more than that from ethanol, resulting in the better waterproof property.

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The extract from steamed sweet potato was found to suppress the melanogenesis of mouse melanoma B 16 cells. The compounds showing the suppression of the melanogenesis in the extract of sweet potato were separated by Toyopearl^(R) HW 40C column chromatography and HPLC. Steamed sweet potato contained chlorogenic acid and three kinds of isochlorogenic acids as the main phenolic constituents. These four phenolic compounds suppressed the melanogenesis equally. The melanogenesis suppressing ratio of the phenolics corresponded to 98% of total suppressing activity of the extract from steamed sweet potato.

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Seven kinds of commercially obtained mushrooms were homogenized with 10 volume of distilled water or saline (wet/vol), and anti-platelet aggregation activity of each water-soluble fraction was compared. One-fortieth volume of Hiratake (Pleurotus ostreatus) and Shiitake (Lentinus edodes) extracts exhibited more than 50% of inhibition of primary and secondary aggregation of human PRP (220×10⁶ platelet/ml) induced by ADP, collagen, or thrombin. They were dark yellow solutions, maintained more than 90% of anti-platelet aggregation activity after boiling at 100°C for 1h. Six volunteers, 18-37 years of age, were given lyophilized Hiratake extract (ASK-0P)with 500mg/kg body. After 1-3h, the platelet aggregation was decreased, whereas the fibrinolytic activity of EFA and t-PA were increased.

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Tofuyo is a unique fermented soybean protein food which possesses a cream-cheese-like textures. In this study, changes in textures and microstructures of tofuyo prepared by red koji (genus Monascus) and/or yellow koji (Aspergillus oryzae) during fermentation were investigated. The values of breaking stress and breaking energy of tofuyo decreased during a ripening period. The values of each viscoelasticity co- efficient on the creep analysis of tofuyo also decreased during a ripening period. An electron microscopic observation revealed that fat globules seemed to bind with proteins. Moreo- ver, it was found electron microscopically that the structure of soybean protein which formed the body of tofuyo changed from fibriform to small particles which connected each other during fermentation. It was considered that these phenomena were greatly affected by degradation of soybean protein in tofu.

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There was not enough quality information about foreign rice in Japan. Three rice varieties; Akitakomachi, Koshihikari and Sasanishiki from California and Japan were used for investigating physicochemical properties and taste evaluations. Taste tests were carried out according to the Japanese official rice taste testing method determined by the Japan Food Agency. The Californian rice had a lower percentage of sound kernel in brown rice, a smaller light translucency through white rice kernel, a lower protein content and a higher starch iodine blue value in cooking characteristics compared with the counterpart. The sensory evaluation for the Californian rice was bad appearance of white rice and cooked rice, bad aroma and low cohesiveness. Therefore, the Californian rice had lower quality in overall flavor than the Japanese rice because it had an opaque and non translucent appearance, an off aroma and a less cohesive texture. The reason for the low quality of Californian rice was due to the culture conditions, s ch as soil, weather, fertilizer and control.

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The sake lees has been found to be a good growth promoting substrate growth for P. ostreatus. The spawning to first yield obtained for a period of 10 days was 27.1% of the moistened media on the beech wood sawdusts supplemented with wheat bran and sake lees.

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