In this work the use of Fourier transform infrared (FT-IR) spectroscopy coupled with an attenuated total reflectance (ATR) accessory was applied to determine the polymerization degree of straight-chain oligosaccharides. Glucose (G1) was used as monosaccharide and maltooligosaccharides (G2-G7) that from two to seven glucose polymerized were used as straight-chain oligosaccharides. Seven kinds of same concentration sugar solution (G1-G7) were prepared and their infrared spectra were measured. It was shown that the shape of spectra in fingerprint region for G5, G6 and G7 were similar. The partial least-squares (PLS) regression was used to determine polymerization degree of maltooligosaccharides from spectra in fingerprint region. The number of C-O-C group was used instead of polymerization degree because C-O-C group forms additionally on polymerization of sugars. Regression analysis against the calculated value gave a correlation coefficient of 0.999. In order to apply this spectroscopy to on-line prediction of individual sugar concentrations in mixtures, curve-fit of the fingerprint region was attempted to extract the absorption bands affected by polymerization, and three component bands were extracted. The multiple linear regression was used to determine polymerization degree of maltooligosaccharides from spectra in fingerprint region. The number of C-O-C group was predicted by the absorbance of spectra of maltooligosaccharides at three component bands. The comparison between predicted values of the number of C-O-C group and the values calculated by preparation of materials showed good agreement. Especially, accurate agreement was shown for maltooligosaccharides from G1 to G4.

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Nitrite in pickled-vegetable was formed from nitrate with microbial action during fermentation, but this nitrite gradually disappeared following lactic acid fermentation. Though sometimes it was observed that high concentration of nitrite (more than 100mg/l) was kept for a long time. The cause on the abnormal accumulation of nitrite in pickles of chinese cabbage (Brassica pekinesis Rupr.) as the raw material was investigated. Several characteristics were observed on the quality of the chinese cabbage leading abnormal accumulation of nitrite as followings: (1) The level of coliform bacteria count is higher than that of normal vegetables. (2) The content of Soluble nitrogen compounds is higher than that of normal vegetables. (3) The strength of buffer action is higher than that of normal vegetables. It was suggested for cause of abnormal accumulation of nitrite that the nitrate reductable coliform bacteria was alive for a long time because of holding pH value by high-buffer action and the change of microflora was delayed. The addition of lactic acid bacteria as a startar was effective to repress the abnormal accumulation of nitrite in pickles of chinese cabbage.

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It is well known that trypsin- inhibitor (TI) is readily inactivated by heating soybeans in boiling water. Based on the previous results that much better digestibility of parched soybean proteins by trypsin was attained with intact soybeans than with crushed ones due to TI stabilized in crushed soybeans, an investigation was conducted whether or not the similar results are obtained by heating intact or crushed- soybeans in boiling water. TI in intact- soybeans was mostly inactivated after heating 20min in boiling water, whereas TI in crushed- soybeans was still active under the same conditions. It seems that the higher the tissue destruction of soybeans, the lower the rate of TI inactivation. In the case of soybean flour, TI activity of more than 2000 unit per gram was remained. In Japanese dishes, soybeans are thoroughly softened in boiled water under pressure to increase both digestibility and flavor. The above results, however, suggest that heating intact soybeans in boiling water for 10 to 20min is sufficient as far as the digestibility of soybean proteins is concerned.

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In this paper we tried to reveal the distribution of antigenicity in a rice grain. We determined total and salt soluble protein content and the antigen-binding capacity of salt soluble protein in various layer of a rice grain. Salt-soluble protein content was high in outer layer, and it was low and constant in inner layer. The antigen-binding capacity of salt soluble protein was especially high in a layer near the surface of grain. The capacity was remarkably reduced in inner layer of grain. The antigen-binding capacity of high-milled rice was reduced to around 4% of that of brown rice. There were some differences in the distribution of antigenicity of the rice grain among varieties, but the reductional effects of antigenicity by high-milling treatment were constant even among different varieties.

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The oxidative stability of diacylglycerol (DAG) was compared with that of triacylglycerol (TAG) in order to understand the oxidative behavior of DAG during oxidation at ordinary temperatures and for thermal oxidation. The fatty acid composition (C_16:0, 5.7; C_18:0, 2.2; C_18:1, 36:2; C_18:2, 46.7; C_18:3, 8.2; C_20:1, 0.9), tocopherol content (1058ppm), color and other properties of DAG were adjusted to almost the same levels as those of TAG. Each was aerated (40ml/sec) at 40°C for 9 days under ultraviolet radiation and for 32 days without light. Potato chips fried in DAG and TAG at 130°C for 5min were irradiated by ultraviolet light at 20°C for 60min. DAG and TAG were heated at 180°C for 12h While gently stirring. The changes in peroxide value (POV), carbonyl value (COV), acid value (AV), amount of conjugated fatty acids, viscosity and color of each oil during these oxidation processes were measured at regular intervals, while ESR measurement was adopted for the potato chips samples. It was found that the changes in the properties of DAG under the three oxidative conditions were almost the same as those of TAG, except that the induction period for DAG as determined by POV was much longer than that of TAG, and that a decrease in lightness of DAG as determined by color-difference measurement was slightly faster than that of TAG. These results suggest that difference in molecular structure between DAG and TAG would partly influence the oxidative stability during oxidation at ordinary temperatures and thermal oxidation.

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An analytical method was developed for determining bisphenol A (BPA) in canned marine products. A sample was extracted with ethyl acetate and the organic phase was dehydrated through a graphite carbon-anhydrous sodium sulfate column. After defatting by n-hexane/acetonitrile partition, the acetonitrile phase was evaporated and cleaned up on a polystyrene solid-phase cartridge (GL-Pak PLS-2). BPA was determined by GC/MS (SIM) after trimethylsilylation. The recovery of BPA from 20g of canned boiled mackerel containing 2μg of BPA was 93.4±2.5% (n=3), and the sensitivity limit of this quantification was about 10ng/g. We then analyzed BPA in 14 samples of canned marine products by this method. BPA was detected in the range of 21.1ng/g-134.8ng/g in 8 samples. This method should be useful as an analytical method of BPA in canned marine products, due to its simplicity of use and selectivity.

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Since goats have a seasonal cycle in reproduction, it is difficult to make and provide goat's soft type cheese throughout the year. We compared chemical characteristics of Saint Maure cheese made from frozen curd with that made from fresh curd (i.e., intact curd). There was no remarkable effect of curd preservation at -20°C on the extent of proteolysis in curd, though a slight increase was observed in the content of watersoluble protein nitrogen in the frozen curd after three months. Electrophoretic pattern of insoluble fraction at pH 4.2 confirmed that the rate of proteolysis in the cheese made from frozen curd was more rapid than that in the cheese made from intact curd. The content of water-soluble protein nitrogen in the cheese made from the curd frozen for three months also remarkably increased, but the increase in free amino acids was comparatively slow. Although the cheese made from the curd frozen for three months smelled of the tallowy, unpleasant odor originated from fatty acids, it was shown that the flavor of the cheese made from the curd frozen for two months could stand comparison with that from the intact curd.

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The effects of soaking at low temperature on food composition of buckwheat (Fagopyrum esculentum Moench) groats were investigated. From the Edo period this treatment carried out to improve eating qualities of Japanese buckwheat noodle, for example, increase of sweetness, decrease of bitter taste and better feeling on the tongue. Buckwheat seeds were soaked in cold water in 2 weeks and traditionally dried outdoors in winter season at southern Zao area in Yamagata prefecture. Two kinds of buckwheat seeds, before and after soaking in cold water, were prepared to groats. Components were determined using flour of whole groats. After soaking in cold water, almost protein, lipid, carbohydrate, minerals, dietary fiber, and rutin in groats did not elute. However polyphenol was decreased and free amino acids composition was changed. Among of free amino acids, γ-amino-nbutyric acid (GABA) was estimated twice as quantity as before soaking in cold water. These results did not indicate drastically, but showed the possibility of improvements on buckwheat noodle qualities.

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