The aim of this study was the development of miso with high quality and value by mutation breeding of koji molds with superior characteristics. We selected mutants generated by MNNG treatment of koji molds, and obtained two kinds of applicable strains for miso production. One is a high vitamin B₂-producing strain with high neutral protease activity (R2 strain), which is useful for improving the color and taste of miso. The other is a high lipase-producing strain (NT12 strain), which increases miso functionality. We compared each mutant to BF-1, the commercial koji mold used as the control strain, during both laboratory-scale and pilot-scale miso fermentation. The koji manufactured from the R2 mutant showed high protease activity and contained 2∼3 times more vitamin B₂ that manufactured from BF-1. In addition, the miso from the R2 strain showed higher x and y color values than that from BF-1, although the Y value (%) was somewhat lower. It also contained high contents of both formol and water-soluble nitrogen, and its color brightness and umami taste were evaluated well. On the other hand, the koji from the NT12 mutant showed lipase activity about 3 times higher than that from BF-1. The resulting miso using the NT12 strain was high in fatty acid ethyl esters, and showed higher inhibitory effects on the growth of tumor cells in vitro compared to BF-1.

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Ascorbic acid contents of Brassicaceae sprouts were determined. Ascorbic acid contents (per gram fresh weight (/g f.w.)) of the sprouts of Brassica oleracea (cauliflower, broccoli and cabbage) bred out of kale were higher than those of Raphanus and other Brassica spp. Ascorbic acid contents (/g f.w.) of the sprouts of cauliflower were higher than those of other B. oleracea. Ascorbic acid contents (/g f.w.) of the Brassica sprouts of heavier seeds were higher than those of lighter seeds. In the case of Raphanus, similar results were obtained to Brassica. Although the seeds of Brassica were lighter than those of Raphanus, the sprouts of B. oleracea were suggested to biosynthesize a higher content of ascorbic acid than those of Raphanus and other Brassica. The sprouts of Brassicaceae were suggested to contain higher amounts of ascorbic acid than those of other vegetables.

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We developed a novel ELISA kit for cow’s milk detection in accordance with the official Japanese method for extraction (official extraction method), which is used for monitoring the appropriateness of food product labeling in Japan. The monoclonal antibody used in the kit was prepared using native or reduced and carboxymethylated cow’s milk β-lactoglobulin as an immunizing antigen. The newly developed ELISA kit detected cow’s milk protein solubilized in 2-mercaptoethanol and sodium dodecyl sulfate, which is used in the official extraction method. The detectable range of egg protein concentrations was 0.8-50.0ng/mL (equivalent to 0.3-20.0μg/g food). Cross-reactivity with both sheep’s milk and duck’s milk, but not with other food ingredients, was observed. Spike recovery tests using model processed foods showed that recovery ranged from 61.1-77.9%, and intra- and inter-assay coefficients of variation were less than 6.5% and 7.9%, respectively. Based on the official extraction method for quantitative analysis of cow’s milk in specified food ingredients, these results suggest that a simple, monoclonal antibody-based ELISA kit is as effective as the conventional method for cow’s milk protein detection.

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Six common Japanese cultivars of ordinary (non-glutinous) rice (Oryza sativa subsp. japonica), namely Koshihikari, Hitomebore, Akitakomachi, Kinuhikari, Nipponbare and Hinohikari, were obtained from public agricultural experiment stations to investigate the production of reducing sugars during rice soaking, as well as related starch-degrading enzyme activities. Polished rice samples were ground to make rice flour consisting of 13% outer endosperm and 87% inner endosperm. Samples were soaked in water, and the amount of reducing sugars formed was then measured using the Somogyi-Nelson method. α-Glucosidase, α-amylase, and β-amylase activities for all samples were also measured. As a result, significant differences in the production of reducing sugars were found among cultivars. This research also suggested the possibility of region-dependent differences in the generation of reducing sugars. As for enzyme activities, α-glucosidase contributed the most to reducing sugar levels in all cultivars. The enzyme contributing the second most differed depending on the cultivar. Within the inner rice endosperm, which showed the greatest influence on reducing sugar formation, the top two enzymes contributed to reducing sugar formation nearly equally. Enzyme activities showed differing characteristics depending on the cultivar, suggesting the existence of cultivar-dependent differences in the formation of reducing sugars.

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Taro, potato, yam and Japanese radish samples were cut into cylindrical shapes (diameter=29mm; length=40mm (taro and potato), 120mm (yam and Japanese radish), and were used to examine changes in gelatinization enthalpy, electrical impedance, moisture content and thermal conductivity during hot water treatment (100°C). The gelatinization enthalpy was measured with a differential scanning calorimeter (DSC). The onset temperatures of gelatinization of taro, potato and yam were 83.2±0.1, 62.7±0.4, 56.2±1.0°C respectively. To reach these temperatures, hot water immersion for 6min on taro and 3-4min on potato and yam were required. The circular arcs, which are the vector profiles of the electrical impedance and are known as Cole-Cole plots, disappeared after 5min from the beginning of soaking in hot water in all samples. It is supposed that the cell membrane of the sample was disrupted at the time. The transient heat probe method using twin probe was used for the determination of the thermal conductivity. Thermal conductivity of Japanese radish increased at first, and then kept constant. That of taro, potato and yam increased and decreased with the changes in moisture content at the earlier stage of the hot water treatment.

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A large amount of apple pomace is discharged as industrial waste. Apple pomace contains glucosylceramides, details of which remain unclear. In this study, we examined the structure and level of the major glucosylceramide in apple pomace and compared its structure with those of glucosylceramides from other plants. Glucosylceramide from apple pomace was principally composed of 2-hydroxypalmitic acid, 4-hydroxy-cis-8-sphingenine, and glucose. These major components were different from those in glucosylceramides from other marketed plants. Moreover, the structures of pomace glucosylceramides from 10 varieties of apple were similar. The glucosylceramide level in ‘Akane’ was the highest among the 10 varieties at 1.00mg/g dry weight.

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