An artificial diet mixed with persimmon wine residue (PR) was used in cultivating ayu fish in an effort to improve its taste and body color, and for the effective use of leftover PR. There were no significant differences in the fatty acid composition of dorsal meat between PR-feeding and control groups. Measurement of color differences in yellow spots, dorsal fins, ventral fins, and caudal fins revealed that body color of the PR-feeding group was significantly improved compared to the control group. A survey was administered regarding ayu overall, and the survey items “appearance” and “taste” were rated significantly higher in the PR-feeding group than in the control group. From the above mentioned results, it is suggested that as an effective use for PR, a PR-mixed feed can improve preferential attributes of ayu such as body color and taste.

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The aim of this study was to produce doughnuts and pound cakes capable of reducing postprandial glycemia. Proximate composition, in vivo hypoglycemic effect, and palatability of the products were investigated. In doughnuts, mixing ratios of Japanese whole rye, whole wheat, and hard flours were 0 : 0 : 50 (D0), 0 : 40 : 10 (D1), and 40 : 0 : 10 (D2). Total dietary fiber (TDF) level was higher in D1 and D2 than in D0. Blood glucose level was significantly (p<0.05) lower in D1 at 15 min and in D2 at 15 and 30 min than in D0 after 50 g sugar loading in healthy subjects. Acceptability of D1 was higher and that of D2 was lower compared to D0. In pound cakes, mixing ratios of Japanese whole rye, whole wheat, and soft flours were 0 : 0 : 25 (C0), 0 : 20 : 5 (C1), and 20 : 0 : 5 (C2). TDF level was higher in C1 and C2 than in C0. Blood glucose level was significantly (p<0.05) lower in C1 than in C0 at 90 min after 50 g sugar loading in healthy subjects. Samples did not significantly differ in palatability. The results suggest that the selection of main raw materials and the processed food form are important factors in producing bakery products with hypoglycemic effects and high palatability.

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This study focuses on the identification and characterization of wild mushrooms grown on the campus of Rakuno Gakuen University, using DNA sequencing and analysis of functional metabolites. Forty-eight samples of fruiting bodies were collected between June 2012 and November 2014. The samples were hot-air dried and powdered, and subsequently extracted with alkaline hot water to obtain beta-glucans, or 50% ethanol for total polyphenols (TPP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Functional metabolites were assessed by colorimetric assays, using Congo Red reagent for beta-glucans, Folin-Denis reagent for TPP level, and DPPH radical scavenging for antioxidant activity. Total DNA was extracted from each sample and subjected to DNA sequencing for the inter spacer regions of ribosomal RNA gene. Sequencing analysis identified 27 independent species or genus of mushrooms. Beta-glucan contents showed clear differences between species. The TPP levels and DPPH radical scavenging activity showed similar tendencies and were significantly correlated (p<0.0001).

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The taste sensing system based on an artificial lipid membrane is not capable of measuring edible vegetable oils directly. To overcome this challenge, we developed a suitable ethanol extraction method to evaluate the oils using the system. To optimize extraction, measurement error rates, m2, of eight categories of taste information were determined. Each taste was judged to be a distinguishable taste when m2 was less than 50%. As a result, the stepwise-diluted ethanol extraction method with filtration was more suitable and reproducible than either single-step extraction or no-filtration. Clustering results of the taste value data obtained using the system were consistent with the positioning map of edible vegetable oils by sensory evaluation.

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There is considerable demand for 4-aminobutyric acid (GABA)-enriched brown rice because GABA effectively decreases blood pressure and improves mental stability. We examined the effect of early harvesting and additional fertilizer application on the GABA content of rice cultivars with various genetic backgrounds—data applicable to the production of GABA-enriched processed rice foods. Early harvesting and additional fertilizer application at the panicle formation stage or at the full heading stage did not lead to an increase in GABA contents. However, large variations in GABA accumulation were observed among the different cultivars, and one (cv. Bekogonomi) was able to accumulate 40 mg/100 g of GABA. This result suggests that it is possible to develop new GABA-enriched rice cultivars without a large germ for the supplementary health food sector.

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In the preparation of ayu-narezushi, a traditional food in Toyama, Japan, rice-koji is added to the other ingredients and then subjected to a 40-day ripening period. In this study, viable cell counts, pH, organic acids and free amino acids were periodically analysed during ripening. After 8 days of ripening, the number of lactic acid bacteria reached approximately 10⁸cfu/g, and then onward, numbers were maintained in the same order of magnitude. The pH was drastically reduced to 4.8 in the first 8 days of ripening, and was thereafter maintained between 4.6 and 4. Lactate content was drastically increased within the first 22 days. Furthermore, total free amino acids were increased by 22 days of ripening ; thereafter increasing moderately. These results showed that lactic acid fermentation developed rapidly in the ripening of ayu-narezushi made with rice-koji.

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During boiling treatment of sweet potato cultivar, “Suioh” leaves, the contents of caffeic acid (CA), 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid and 3,4,5-tricaffeoylquinic acid (3,4,5-triCQA) were significantly decreased. However, no significant changes of 4-caffeoylquinic acid and 3,4-dicaffeoylquinic acid were observed, and the content of 4,5-dicaffeoylquinic acid was significantly increased. When each standard solution of CA and caffeoylquinic acids (CQAs) were heated to 100°C, structural isomers were generated from mono-CQAs and di-CQAs, although no significant changes were observed in CA and 3,4,5-triCQA. Therefore, differences in the contents of CA and CQAs during boiling treatment of “Suioh” leaves might be attributed to the formation of structural isomers of mono-CQAs or di-CQAs, in addition to the broth outflow of CA and CQAs in the leaves.

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