The taste characteristics and physical properties of following varieties were measured: Koshihikari, Sasanishiki, Akitakomachi, Variety A (high amylose rice), Variety B (high protein rice) and Nipponbare. The following results were obtained. The creep measurement for one grain of cooked rice could be analyzed corresponding to a Voigt form model of six factors. As a result, it was observed that the creep compliance curves immediately after rice cooking were high in the order of Koshihikari > Akitakomachi > Sasanishiki > Nipponbare > high protein rice > high amylose rice, and that Koshihikari was soft. When preserving cooked rice, little change was observed both in elastic modulus and viscosity coefficient with refrigerated preservation, however, an increase in the viscoelastic coefficient was observed in cold preservation, and a tendency was observed for retrogradation to take place due to cold preservation, and hardening proceeded. In particular, the high amylose rice provided remarkable results, however, it was clarified that little progress in hardening was provided by cold preservation in the case of Koshihikari and Akitakomachi. As a result of extracting the strength or weakness of taste characteristics in the sensory evaluation by means of factor analysis, the first factor was taste and glutinousness, the second factor was texture such as hardness and chewiness, and the third factor was relating to flavor and appearance such as fluffiness. The ratio of contribution was 39.8, 36.5 and 23.7%, respectively. For preference, the first factor was taste and shape, the second factor was texture such as hardness, glutinousness and chewiness. The ratio of contribution was 57.6 and 42.4%, respectively. As a result of a multiple regression analysis, the evaluation items for preference that most affected the overall evaluation were feeling in mouse, fluffiness, after-taste, stickiness, sweetness, luster and chewiness.

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For the purpose of preventing food spoilage, bactericidal and bacteriostatic effects by hydrostatic pressure treatment with addition of allylisothiocyanate (AIT) were examined. When the vegetative cells of bacteria suspended in a phosphate-buffered saline (pH7.2) without AIT were treated under hydrostatic pressure at room temperature for 10 min., the sterilization required 300 to 500 MPa condition. In the case of spores of Bacillus subtilis, it was not found any effects on the sterilization until 600 MPa condition. In comparison of two strains of Escherichia coli, type CR-3 was more resistant against hydrostatic pressure than another one. Most microorganisms including E. coli CR -3 were sterilized at 200 or 300 MPa with addition of small amount of AIT, however, Staphylococcus aureus and spores of B. subtilis were not killed in these conditions. In the examination of the growth curve of each strain, the lag phase of the strains treated under 200 MPa with addition of AIT was prolonged more than that of non-treated ones. Application of hydrostatic pressure treatment with AIT for preservation of "Asazuke" (low salted vegetables) was effective for extending the shelf life of the product.

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Properties of sponge cakes and its batters replaced for sucrose by seven sugars (such as glucose, maltose, lactose, erythritol, sorbitol, maltitol and lactitol) and their combinations were investigated, and effects of sucrose replacement on baking process of the sponge cakes were discussed. The batters having higher specific gravity made lower relative volume of cakes. These batters included low solubility sugars. The transition peak temperature (Tp) of batters measured by differential scanning calorimetry ranged from 79.2°C to 93.2°C. The Tp were corresponded to the temperature which made drastic change in structure of each batter. The batter Tp correlated with the increase rate and the maximum of cake temperature, and with the initiation time of cake shrinkage during baking. Formation period of sponge structure in the central part of cake (initiation time of cake shrinkage - corresponding time to batter Tp) versus Tp plots showed a linear correlation (r=0.96). There was a correlation, which was approximated by a quadric equation (r=0.93), between the batter Tp and the relative volume of cake. These results indicated that sucrose replacement varied the batter Tp, and the Tp influenced on cake temperature and sponge structure formation during baking, and consequently on the cake volume. The cakes obtained by sucrose replacement showed various texture profiles. Further study was required to evaluate acceptability of these cakes.

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It is known that a white precipitate is formed in the green tea extract infused with hard water. The13 C-NMR spectrum of the precipitate agreed with that of calcium oxalate. The oxalic acid concentration, analyzed by using a newly developed capillary electrophoresis method, in the green tea extract infused with hard water was lower than that with distilled water. These results show that the precipitate is calcium oxalate. The effect of oxalate on tea taste was also discussed.

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For the preservation of "Asazuke" (nonfermented pickles of cucumber), antimicrobial action of chitosan against lactic acid bacteria isolated from deteriorated pickles was investigated. Appearance of turbidity in the liquid part of pickles during storage was caused by growth of lactic acid bacteria, in which Lactobacillus sake and Leuconostoc mesenteroides were found. Almost all the bacteria died out by a treatment with 0.01% of chitosan solution dissolved in 1% acetic acid (pH 5.5) for 60 minutes, but this bactericidal action was lowered in the coexistence of salt, carrageenan, or sodium mono glutamate, respectively. Under the similar conditions, 3% salt and pH 5.5, to Asazuke, the combined use of 0.05% chitosan and 1% glycine, or 2% ethylalcohol was effective in inhibition of the growth of these lactic acid bacteria.

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For the production control of potato starch, four characteristic parameters such as the amount of starch content, water-insoluble and soluble materials and moisture content are coming more attention than previous traditional chemical analyses in laboratories. Potato pulp is a base of water-insoluble by-products and soluble wastes from starch manufacturing cause high BOD load. The authors have elucidated how the four characteristic values are interchanged among the factory operations, rasping decanting and purifying. For the process calculation, a set of 37 equations was derived from fundamental considerations. As the numerical results, it was possible to determine the rare starch and two by-products of potato pulp and waste water using the above four characteristic parameters for the potato feed, and the ratio of rasping.

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The trehalose content in natural and fermented foods was analyzed by gas chromatography (GC). The samples were prepared by extraction from each food with 80% ethanol aqueous solution. For the GC analysis of sugar, an OV-17 packed column and a DB-5 capillary column were used. Trehalose was detected in relatively large quantity in mushrooms and baker's yeast. The trehalose content of dry solid materials ranged from 10% to 23% for mushrooms and from 7% to 11% for baker's yeast. Trehalose was also detected in alcoholic beverages (sake, beer and wine), mirin, bean products, shrimp, mozuku and hijiki. The trehalose content of each was 39-240ppm, 260ppm, 5 -150ppm, 5-5000 ppm, 4 ppm and 2700 ppm, respectively. Wakame, konbu and honey have also been reported to contain trehalose, however, it was not detected in those materials in this study.

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