This study investigated the effects of storage of stone-milled buckwheat flour on its flavor and texture using sensory evaluation and instrumental analyses. Samples of stone-milled buckwheat flour were stored for 0, 7, and 14 days at 25°C in kraft bags and then their taste, scent, and texture were measured. The moisture content in the samples decreased with increased storage period. On taste evaluation, samples with a longer storage period had significantly higher scores for bitterness and astringency compared with the control samples that were not stored (P<0.05, Student's t-test). Moreover, instrumental analysis with taste sensors revealed significant differences in some sensor outputs relative to the storage period (P<0.05, Student's t-test). In contrast, on scent evaluation, samples with a longer storage period had lower scores, while on instrumental analysis using GC-MS, the total amount of flavor components decreased with increased storage. On texture evaluation, hardness significantly increased as the storage period increased (P<0.05 ANOVA), while instrumental analysis using a texture analyzer revealed a decrease in elasticity with increased storage. These results showed that prolonged storage of stone-milled buckwheat flour alters its taste, scent, and texture. The instrumental analyses used in this study were valid for quantitative evaluation of such sensory changes.

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The breaking properties of baked products such as cookies made from rice powders or starches were compared with those made with wheat flours or starches. Using non-glutinous rice resulted in baked products with the maximum stress and elastic modulus, which enhanced with increased relative humidity. The breaking properties of glutinous rice powder products were lower than those of non-glutinous rice powder products but higher than those of wheat powder products, while the breaking properties of rice starch products were similar to those of rice powder products. Total energy showed a strong correlation with swelling capacity and energy and starch solubility for all baked products. The baked rice powder products increased in hardness relative to increased paste materials, increased density and the amount of non-homogeneous structures.

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To determine the geographic origin of the garden pea, 79 samples from Japan and China were examined. Nine elements contained in the garden pea were determined by ICP-MS. Principal component analysis of these elements could discriminate garden peas from Japan and China. We thus developed a linear discriminant analysis (LDA) model established based on the results of Sr and Pb, which were chosen by backward stepwise regression. This LDA model identified the origin of garden pea from Japan and China with 100% accuracy.

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Methanol extracts of 105 plant parts from 101 different edible plants were screened against three food-borne microorganisms, Bacillus cereus, Leuconostoc mesenteroides, and Saccharomyces cerevisiae. As the extract from unripe Japanese plum yew fruit (Cephalotaxus harringtonia) was the most efficient at inhibiting the growth of B. cereus and L. mesenteroides, its antibacterial activity was evaluated against 22 species of Gram-positive bacteria, 7 species of Gram-negatives bacteria, and 13 species of fungi, using the broth dilution method. The extract exhibited antibacterial activity against Gram-positive bacteria with minimum inhibitory concentrations (MIC) of 25 to 200μg/ml in agar broth and 5 to 40μg/ml in liquid broth. Moreover, the antimicrobial effect was stronger under acidic and basic conditions than neutral condition. In contrast, no antibacterial activity was observed for Gram-negative bacteria and fungi (MIC, >1000 μg/ml).

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We examined the effect of heat treated Enterococcus faecalis FK-23 on anti-obesity. C57BL/6J mice (male, 5 weeks old) were fed control diet (Control group), high fat diet (High fat group) or high fat diet supplemented with 2% E. faecalis FK-23 mixture in water (FK-23 group) for 67 days. The effect of FK-23 on body weight, food intake, percent body fat, fat mass, epididymal fat pad weight, liver weight, lipids in liver, blood glucose, total cholesterol, adiponectin and leptin of these obese mice was examined. Body weight, fat mass, epididymal fat pad weight, blood glucose and leptin were significantly different between mice fed the high fat and FK-23 diets, while differences in food intake, percent body fat, liver weight, lipids in liver, total cholesterol and adiponectin were not significant.

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The potential prevention of metabolic syndrome was investigated using polyphenols extracted from chestnut skins, which are waste products of confectionary manufacturing. The major polyphenol of chestnut skin was found to be condensed tannin. This chestnut skin polyphenol strongly inhibited the activity of pancreatic lipase with 4-methylumbelliferyl oleate and triolein as substrates. The suppression of lipid absorption was examined by administration of 125mg/kg and 500mg/kg chestnut skin polyphenol in rats. A significant dose-dependent decrease in blood triglyceride levels was observed (p<0.05). These results suggest that chestnut skin polyphenol has potential as an anti-metabolic syndrome substance.

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[in Japanese]

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