Salt-tolerant yeast, Saccharomyces rouxii and Torulopsis versatilis, and salt-sensitive yeast, S. sake, were cultivated in media containing sodium chloride, and in made without sodium chloride, and the cell wall content and the chemical composition of the cell walls were compared. (1) The salt-tolerant yeast had a higher cell wall content than the salt-sensitive yeast. (2) The mannan content in cell walls of both types of yeast decreased when cultivated in media containing sodium chloride. The chitin content in the cell walls of salt-tolerant yeast decreased when cultivated in media containing sodium chloride, while the chitin content of salt-sensitive yeast was low. The protein content increased in both types of yeast when cultivated in media containing sodium chloride. The above results showed that there is a relationship between the salt tolerance property of yeast and the poly-saccharide and protein content in cell walls.

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Almond β-glucosidase was immobilized by a radiation-polymerization method in a frozen state. The most suitable monomers to give highest activity retention (72%) were polyvinyl alcohol and magnesium acrylate with N, N'-methylene bis acrylamide. No leakage of β-glucosidase from the polymer matrix was observed. Compared with free β-glucosidase, the immobilizen enzyme exhibited (1) improved stability at the acetate buffer concentration of 20-40mM. (2) pH optimum shifted to 4.5 from 5.2 and improved stability at lower and higher pH. (3) A similar optimum reaction temperature, 55°C, but improved thermalstability. (4) Higher apparent Km (20.8mM) for cellobiose compared with Km (5.6mM) of free enzyme.

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In order to confirm the solubilization of insoluble alginate of wakame (Undaria pinnatifida) fronds, with boiling, water soluble materials were removed by extracting with water from the fronds as the first stage, then both the insoluble and solubilized polysaccharide contents, and the metal (Na, K, Mg, Ca) and the alginate (acid-soluble and-insoluble) contents of polysaccharides of the fronds were determined before and after boiling. Furthermore, the change of the properties with boiling such as polymerization index, activation energy and the bound water content of the alginate was examined, where the polymerization index was defined for convenience as the amount of alginate (mg) consuming a microequivalent of iodine. The results obtained are as follows. It was observed that the solubilization of insoluble polysacchcarides occurred, and that the alginates occupied 95% or more of each of solubilized and insoluble polysacchcarides. These alginates were partly converted to acid soluble form from acid insoluble orm with boiling. The insoluble polysaccharides which have low calcium contents appeared to be soluble with boiling, on the contrary, the polysaccharides which remain insoluble in spite of boling for four hours have remarkable high calcium contents. The lowering, in process of boiling, of both the polymerization indexes and sedimentation constants of both the solubilized and the insoluble alginates was observed, but the activation energy and the bound water content of the insoluble alginate which were determined by thermogravimetric analysis and by pulse NMR analysis, respectively, did not change to much extent with boiling.

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Protein patterns of 'Sordum' plums were studied by the use of polyacrylamide gel disc electrophoresis. The protein components recognized in the gel (pH 9.4) were twelve in the fruits of three maturities, unripe (UR), commercial ripe (R) and full ripe (FR). A little difference of the amount of each protein component was observed among three maturities. Changes of protein patterns of the fruits stored at R maturity were as follows; (1) The amounts of most of the protein components of the fruits stored at 20°C increased at the beginning of storage. After storage for 7 days, most of the components disappeared. (2) Protein patterns of the fruits stored for 11 days at 30°C were the same as those at the beginning of storage. During storage, the amounts of protein components tended to rise and new components also appeared. But most of these components disappeared after storage for 15 days. (3) Protein components of the fruits stored at 20°C after prestorage at 30°C rapidly disappeared and at 30°C after prestorage at 20°C ended to be recovered. When FR plums were stored at 30°C, some protein components disappeared after 4 days and did almost all after 7 days.

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A preparation of ascorbate oxidase (AAO, EC 1.10.3.3) was obtained from the peel of young fruit of Satsuma mandarin (Citrus unshiu Marc., 1-3cm in diameter). The effects of temperature and pH on the AAO activity were studied using the difference spectral method described previously. The enzyme showed strong activity at the temperature from 30 to 35°C and at pH about 5.5. It was stable at a temperature below 50°C and in the pH ranges of 5 to 9. On the basis of these results, we carried out the enzymatic oxidation of L-ascorbic acid (AsA) at 30°C at pH 6. A linear relationship was observed between the AsA oxidation, which was expressed as a peak height of difference spectra (ΔE₂₄₃), and the reaction time, within 10min. The rate of the AsA oxidation was proportional to the amount of the enzyme present. This shows that the oxidation rate can be adopted for determining AAO activity. The AAO activity in the peel of Satsuma mandarin during fruit ripening was measured by this difference spectral method. The strong a ctivity was found in a young fruit and it sharply droped as the fruit developed.

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Lipid and fatty acid composition of total lipids in seeds and endocarps of three cultivars ('Kurakata-wase', 'Okubo' and 'Yamane') of unripe and ripe peaches, Prunus persica Batsch var. vulgaris Maxim. were investigated by means of silicic acid column chromatography, thin-layer chromatography, thin-chrography and gas-liquid chromatography. The results obtained were as follows: (1) In the case of three cultivars, the amounts of total lipids and neutral lipid fraction in seeds of ripe peaches were higher than that of unripe fruits. On the other hand, the amounts of total lipids, neutral lipid, glycolipid and phospholipid fraction in unripe endocarps were a little higher than that in ripe. (2) Triacylglycerol content in neutral lipid fraction in ripe seeds was very high. In both unripe and ripe endocarps, sterol content was high. (3) Acylsterylglucoside, monogalactosyldiglyceride, sterylglucoside, cerebroside and digalactosyldiglyceride were identified in glycolipid fraction in seeds and endocarps of unripe and ripe peaches. In the above lipids, acylsterylgucoside content in both seeds and endocarps of unripe peaches was very high. On the other hand, phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine and phosphatidylinositol were identified in phospholipid fraction, but remarkable changes of the above lipid content were not observed in the stage of maturation. (4) Main fatty acids of total lipids, neutral lipid fraction, glycolipid and phospholipid fraction in unripe and ripe peaches were 18:1, 18:2 and 16:0 acids in seeds and 18:3, 16:0 and 18:2 acids in endocarps. Changes of each fatty acid content in the stage of maturation were observed in seeds, but not in endocarps.

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Lyophilized soybean proteins gelled by addition of phosphate buffer, after they were stored at relative humidity (RH) 96% and 50°C and allowed to absorb moisture. Textural properties of humidity-induced gels were investigated using mechanical testing techniques. Seven S globulin gelled in a day after moisture sorption, acid-precipitated protein (APP) in 3 days and 11S globulin in 5 days in case of using the phosphate buffer of ionic strength of 0.5. Gelation of APP and 7S globulin was suppressed at ionic strength of 0.01 and 0.1. On the other hand, gelation of 11S globulin was promoted at ionic strength of 0.1. When humidity-induced gels were heated at 90°C for 30 min, hardness of gels increased to 4 to 15 times that of unheated gels. Furthermore, heating the humidity-induced gels made their hardness firmer than that of gels formed by only heating. Microstructures of humidity-induced gels were also investigated using a scanning electron microscope.

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Influences of sub-zero temperature and in-package atmosphere on the quality of dried laver, Porphyra yezoensis, were investigated. Retention ratios of chloropyll, total ascorbic acid and biliproteins (phycoerythrin and phycocyanin) were evaluated at intervals to assess the quality. (1) At 30°C and a moisture content of 9.1%, degradation of chlorophyll and ascorbic acid were very rapid. The degradation was significantly but not completely controlled by packaging the sample with nitrogen. After storage for 11 months at a moisture content of 3.0%, the retention ratio of ascorbic acid was 44.7%, while the chlorophyll was fairy stable. (2) At -20°C and -50°C, chlorophyll slightly degraded at a moisture content of 9.1%. But this destruction ratio was almost the same as that in the laver containing a moisture of 3-5% stored at 30°C. After the storage of 11 months at -20°C, the retention ratio of ascorbic acid was 69% and 85% at moistures of 9.1% and 3.0%, respectively. (3) Biliproteins degraded in almost the same manneras chlorophyll, althrough they were more stable than chloropyll. (4) Nitrogen gas packaging had remakable effect on the prevention of the pigment and ascorbic acid degradation at 30°C, but had little effect at -20°C and -50°C. In conclusion, storage under sub-zero temperature of -20°C and -50°C prove to be effective for the preservation of laver, but it must be noticed that some extent of deterioration of ascorbic acid takes place even at -50°C.

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Antioxidative activity of miso was compared with known antioxidants including tocopherol, ascorbic acid and phytic acid. Synergistic effect of miso on those antioxidants and antioxidative activities of antioxidants prepared from miso were also Studied. (1) Synergistic effect of miso on antioxidative activity of tocopherol was recognized. However, the effect of miso on ascorbic acid and phytic acid was very weak. (2) Antioxidative activities of the antioxidant preparations from miso and their activity changes during storage for three months at 45°C were determined. Tocopherol: miso (2:8) and tocopherol: miso: ascorbic acid (2:7:1) preparation showed strong antioxidative activities and their activities increased during storage.

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The activities of sucrose synthase and sucrose phosphate synthase in potato tubers or sweet potato roots were enhanced by an irradiation treatment and reached maximum levels several days after irradiation and then decreased. The activities were at a high level when surcrose was accumulating in irradiated samples. It was suggested that surcrose synthase and sucrose phosphate synthase played an important role in the accumulation of sucrose in both irradiated potato tubers and irradiated sweet potato roots.

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