In this study, we investigated the concentration of food derived-peptides in blood following oral intake of chicken collagen hydrolysate (chicken-collagen octa peptides ; C-COP) and measured the angiotensin-converting enzyme (ACE) inhibitory activity of these peptides. Healthy volunteers ingested the C-COP solution (25g/60kg body weight) after fasting for 12h. The peptide-formed hydroxyproline (Hyp) significantly increased and reached maximum levels (91.1μM) 2h after consumption. Pro-Hyp, Leu-Hyp, Pro-Hyp-Gly, Phe-Gly, Ala-Hyp, Hyp-Gly, Glu-Hyp-Gly, Ala-Hyp-Gly and Ser-Hyp-Gly were detected in human blood, possessing ACE-inhibitory activity. Of them, Ala-Hyp (IC₅₀ : 0.177mM) had the strongest ACE inhibitory activity. Thus, C-COP appears to absorb with the peptides by enzymatic digestion in blood, thereby inhibiting ACE, suggesting that food-derived collagen peptides are related to antihypertensive effects.

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The reduction of ferric ion to ferrous ion and dialyzable iron in lactose solution (4.8, 6.0 and 7.2%), milk protein solution (3.3%), and a combined (lactose-protein) solution containing 250ppm of FeCl₃ was investigated in connection with iron bioavailability. Each protein solution was adjusted to the following ratios of whey protein to casein (W/C), 0 : 10, 2 : 8, 4 : 6. 6 : 4, 8 : 2, and 10 : 0, and then treated with an enzyme (pepsin, pancreatin-bile salt). Following dialysis of these solutions, the concentrations of ferric and/or ferrous ion, and dialyzable iron were determined. The concentration of ferrous ion was higher in 6.0% and 7.2% lactose solutions than in 4.8% lactose solution. The enrichment of whey protein in the protein solution increased the concentration of ferrous ion and dialyzable ion. In the lactose-protein solution, the concentration of ferrous ion and dialyzable ion was higher at the W/C ratio of 6 : 4 and 7.2% lactose, but lower at 2 : 8 and 4.8%.

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Extract of decaffeinated green coffee beans (EDGCB) was prepared by supercritical CO₂ treatment and alcohol extraction and contained 38% (w/w) chlorogenic acids (CQAs, consisting of 8 kinds of chlorogenic acid isomers). The effects of CQAs in EDGCB on inhibitory contribution of amylolytic enzymes (α-glucosidase and α-amylase) were examined in vitro. The activity of these amylolytic enzymes was inhibited depending on the EDGCB concentration, and CQAs significantly contributed by 63.1-85.8%. Comparison of CQA isomers showed that inhibitory activities of di-caffeoylquinic acids (3,5-diCQA, 3,4-diCQA and 4,5-diCQA) were the strongest, followed by those of caffeoylquinic acids (3-CQA, 5-CQA and 4-CQA) and feruloylquinic acids (5-FQA and 4-FQA) in α-amylase and sucrase. 3,4-diCQA was the main active component in EDGCB for inhibiting maltase. The number of caffeoyl groups and the binding position for quinic acid significantly affected the inhibitory activity of CQAs. The effects of EDGCB on the inhibitory activity of α-GI (acarbose or voglibose) in vitro and on the postprandial blood glucose level were next examined using rats. Addition of EDGCB to the reaction mixture with a low concentration of α-GI showed additive inhibitory effects of each enzyme. Moreover, EDGCB prevented the increase in blood glucose level in vivo. These results suggest that EDGCB is useful for prevention of postprandial hyperglycemia.

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The effects of the roller material used in mill and liming treatments on the color tone, nutritional and functional components and sensory characteristics of non-centrifugal sugar were investigated. The iron roller in mill and liming treatments was responsible for the dark color in commercially available non-centrifugal sugar, suggesting an acceleration in the amino-carbonyl reaction by iron during the liming treatment. Use of the stainless-steel roller in mill but not liming treatment depressed the amino-carbonyl reaction, resulting in a light tone non-centrifugal sugar. The light tone non-centrifugal sugar had lower iron and calcium contents than that obtained using the iron roller for the same treatment. No difference in potassium and magnesium content, amino acid components, sucrose content, and polyphenolic content was observed between the light tone and dark tone non-centrifugal sugar when the iron roller was used in the combined mill and liming treatment. Moreover, the light tone non-centrifugal sugar was superior to the dark tone using the iron roller in the combined treatment on the sensory evaluation.

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We examined the effect of fermented soybean milk by Enterococcus faecalis TN-9, which was isolated from deep-sea water in Toyama Bay, on anti-obesity. The effect on body weight, food intake, percent body fat, fat mass and blood biochemical analysis of the ovariectomized Sprague-Dawley rats were examined. The rats were divided into the following 5 groups : 1) Control, ovariectomized (OVX)+saline at a daily dose of 5mL/kg body weight ; 2) Soy milk, OVX+soy milk at a daily dose of 5mL/kg body weight ; 3) Low dose, OVX+fermented soy milk at a daily dose of 2mL/kg body weight ; 4) High dose, OVX+fermented soy milk at a daily dose of 5mL/kg body weight ; and 5) Sham, sham operated rats. There was a significant difference in fat mass and food intake between the control and high dose groups, but no significant difference in body weight, percent body fat, triglycerides, free fatty acids and cholesterol among all ovariectomized groups. These results indicate that fermented soy milk suppresses the elevation in fat mass in ovarian hormone-deficient rats.

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Changes in copper content of were studied using Fuji apples grown in an experimental orchard of National Institute of Fruit Tree Science, Morioka in 2001. The effect of fungicide application (Bordeaux mixture including copper) on the concentration of copper was observed only in the peel of apples harvested until 1980. Following the substitution of the Bordeaux mixture for organic germicide from 1986 in the same orchard, this study investigated the copper content in different parts of apples picked from June 4 to November 12 (corresponding to one ripening season) at an interval of 4-5 weeks. Apples were separated into peel, pulp, core and seed immediately after picking for determination of copper content. Copper contents of pulp harvest time in 2001 and 1980 were same (0.05mg/100g raw). The copper content in pulp, core and seed in 2001 was consistently higher than that in 1980, throughout the ripening season. The content in raw apples without and with skin were the same in 2001 (0.053mg/100g).

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This study presents for the first time a microwave-assisted method used to extract useful components from dried peels of Citrus yuko Hort. Polymethoxyflavones were extracted from dried peels of C. yuko for 2.5 to 5min under reflux with stirring in methanol. Tangeretin (4′,5,6,7,8-pentamethoxyflavone) and nobiletin (3′,4′,5,6,7,8-hexamethoxyflavone) were isolated in 0.12% and 0.10% (w/w) yields, respectively. Hesperidin, which has been isolated previously from peels of C. yuko, was also isolated in this study and hydrolyzed to give hesperetin. The structures of these polymethoxyflavones were confirmed on the basis of spectroscopic, elemental and HPLC analyses. The microwave-assisted extraction is a more rapid and efficient method than conventional thermal heating extraction.

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We analyzed low-adhesive and ordinary chewing gums for their adhesiveness to the different types of dental materials using instrumental measurement and a sensory questionnaire. The questionnaire results were compared between two panels of elderly and young individuals. 1) Adhesiveness measurement : Under dry conditions, adhesiveness of low-adhesive chewing gum was significantly lower than ordinary chewing gum. While differences under wet conditions among the types of materials were not observed, adhesiveness was notable using a plunger made of acrylic resin but low using plungers made of stainless steel or ivory. 2) Sensory questionnaire of adhesiveness : In two groups that use dental resin material, the “treated with other material” and “full denture using” groups, sensory adhesiveness of low-adhesive chewing gum was significantly lower than ordinary chewing gum in both panels. In the total response of the “treated with metal material” group, differences in sensory adhesiveness of both chewing gums was more significant in the elderly panel than in the younger panel. This difference may be attributed to the degree of dry mouth symptom in individuals of different ages. Taken together, wet conditions appear to be the optimal conditions to determine sensory adhesiveness of chewing gum for younger and healthy elderly people, while dry conditions appear to be optimal for people with dry mouth symptom. Moreover, these results suggested that low-adhesive chewing gum causes less adhesiveness regardless of the degree of dry mouth symptom.

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A peptidase that hydrolyzes benzyloxycarbonyl(Z)-Gly-Gly-Arg-4-methylcoumaryl-7-amide (MCA) was purified from dormant wheat seeds (Triticum aestivum). The activity of the peptidase was optimum at pH 7.5 and was inhibited by serine protease inhibitors. The peptidase degraded wheat gliadin epitopes, PQQPF and QQPFP, which were recognized in sera from patients with atopic dermatitis. In contrast, the wheat glutenin epitope, QQQPP, was not degraded by the peptidase.

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