The gelatinization of starches in cotyledon cells of Tutankhamen's pea (Pisum sativum) was studied. The loss of birefringence of starches in cells was low in the temperature range of 50 to 70°C, compared with those of isolated starches. While the differential scanning calorimetry curve of cells was similar to that of isolated starches, the onset temperature of endotherm was slightly higher than that for isolated starches. The solubilities and swelling power of starches in the cells were also low compared with those of isolated starches. From these results, it was concluded that the gelatinization starches inside cotyledon cells of tutankamen's pea was suppressed as well as those of adzuki, kidney and faba beans. Thus, it was suggested that Tutankhamen's pea was suitable for production of an (bean jam).

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We aimed to detect the allergen proteins in food materials using recently developed near-infrared fluorescent probes. Sensitivities of this method were comparable to chemiluminescence detection methods, which are known to be sensitive. In addition, the sensitivities of this near-infrared fluorescent method were at least 10-50-times higher than those of the conventional visible fluorescent methods using Cy3 and Cy5 dyes. This method was effectively applicable to immunoblotting, dot-blotting and plate-assay (direct FLISA : fluorescence-linked immunosorbent assay) with ELISA plate. Allergen levels of the food sample were quantified by standard curves using standard allergen protein using the dot-blotting technique. This highly sensitive detection system also provided multiple detections of different allergens for different antibodies and dyes with distinct properties of wavelength. This enables high-throughput screening of characteristic allergen contents of target food materials, or cultivars. Generally, allergen proteins are recognized by patient's serum IgE. Therefore, we tried to detect patient's IgE-binding proteins, the putative allergens in foodstuffs. In this detection system, it was possible to detect IgE-binding proteins with sensitivity almost equivalent to a chemiluminescent detection system. Taken together, it was shown that this novel detection system was an effective technique for the sensitive detection and screening of food allergens.

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The mean body weight of male mice fed a high-fat diet and seaberry leaf polyphenols (SBLPP) juice for eight weeks was significantly lower than that of controls, with the weights of abdominal adipose tissue and liver being particularly low. Additionally, blood GTP activity in experimental mice was significantly lower than in controls, demonstrating the inhibitory effects of SBLPP juice on development of fatty liver, which may otherwise be induced by a high-fat diet. Furthermore, expression of acyl-CoA oxidase (ACO), medium-chain acyl-CoA dehydrogenase (MCAD), and fatty acid beta-oxidization enzymes significantly increased in experimental mice. In vitro experiments showed that SBLPP juice suppressed pancreatic lipase activity in a concentration-dependent manner, with IC₅₀ being 4.5ppm. It was therefore suggested that, in mice fed a high-fat and SBLPP juice diet, gene expression of fatty acid beta-oxidation enzymes in the liver was enhanced, which increased the lipid metabolism and inhibited the pancreatic lipase activity, thus reducing lipid transportation to the body and increasing fecal lipid excretion. As a result, body fat deposition was inhibited.

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In recent years, there has been a need for a new quality criterion for antioxidants based on its antioxidative activity in Japan. In particular, novel official methods of evaluating the antioxidative activities of food additives are required. In order to investigate the possibility of developing official methods, the reproducibilities of three simple conventional antioxidant assays (DPPH assay, ABTS assay, and WST-1 assay) based on spectrophotometric detection were evaluated by collaborative study between three laboratories. DPPH and ABTS assays were performed to evaluate the antioxidant activity (TEAC, Trolox equivalent activity) of all nine antioxidants used in this study, whereas the WST-1 assay was suitable for evaluating the superoxide dismutase (SOD)-equivalent activity of seven antioxidants (excepting D-α-tocopherol and D-δ-tocopherol). The HorRat values from the collaborative study revealed that the DPPH and ABTS assays showed higher reproducibility than the WST-1 assay. It was assumed that the lower reproducibility would be due to the measuring principle, because the WST-1 assay, unlike the DPPH and the ABTS assays, is a competitive enzyme assay. Based on the results, we concluded that the DPPH and ABTS assays would be candidates in validation studies of methods for the purpose of developing an official methodology.

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In our previous studies, 445 Japanese texture terms were collected through questionnaires completed by texture researchers and analyzed for consumer recognition. The present study investigated consumers' vocabulary for food texture according to gender, age and region using the data set. A 75% recognition criterion was used as the minimum level for consumers' vocabulary. Results indicated that females seemed to have a larger vocabulary for food texture than males. Younger consumers (junior high school students and 18-34 years old) had a smaller food texture vocabulary compared to middle-aged (35-49 years old), mature (50-64 years old) and elderly (over 65 years old) age groups. Consumers living in metropolitan areas seemed to have a larger food texture vocabulary than consumers in the Kyoto-Osaka-Kobe area. Logistic regression analysis was used to test for significant differences in term recognition among demographic attribute groups. Results showed that recognition of terms such as “mottari” (sticky, viscous or glutinous), “burin-burin” (quivery or firm), “boso-boso” (dry and tasteless) differed according to consumer gender, age and/or region of residence. It was considered that several factors such as eating experience, food's boom, popular expressions and dialect could explain these differences.

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Changes in antioxidant activity of miso by variety, cooking method and added spices were investigated. Antioxidant activity of miso increased in proportion to brightness of color and content of total isoflavones and their aglycones. The order of increasing antioxidant activity by variety was soybean-koji miso, dark yellow rice-koji miso, barley-koji miso, light yellow rice-koji miso and sweet rice-koji miso. In increasing order, boiling, frying, broiling or canning of miso enhanced browning and antioxidant activity of miso, while total isoflavones and aglycones contents were decreased. When miso was cooked by microwave, browning and degradation of isoflavone aglycones were decreased. The antioxidant activities of miso cooked with spices did not correlate with their polyphenol compound content. When miso was cooked with ginger, the isoflavone aglycone content decreased, while antioxidant activity and polyphenol compound content increased. When miso was cooked with garlic, mustard, red pepper or sesame, antioxidant activity and browning of miso were remarkably decreased while isoflavone aglycone content was unchanged. These results suggested that antioxidant activity of miso was more affected by melanoidin content formed during cooking more than isoflavone and polyphenol compound content. Based on the above results, ginger may enhance the antioxidant activity of miso by addition of its strong antioxidant compounds, while garlic, mustard, red pepper and sesame may depress miso antioxidant activity by suppressing melanoidin formation during cooking. We expect that cooking miso with spices increases its useful health benefits compared to unseasoned miso..

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[in Japanese]

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