Apple pectin oligosaccharide (APO) prepared from apple juice residue contained about 30% uronic acid, the principal component of pectin. We found that APO is utilized by major species of human intestinal microflora, such as Bacteroides sp. and Bifidobacterium sp., and that it induces the production of short-chain fatty acids, mainly acetic acid and butyric acid. Moreover, APO was observed to reduce fecal putrefaction by fecal batch culture test. Since APO is expected to be effective for improving intestinal function, APO (5g/day) was administrated for 2 weeks to 7 subjects who tended to be constipated. Intake of APO led to an increase in bowel movement frequency and improved fecal condition, including fecal odor. Thus, APO intake may contribute to improving intestinal disorders.

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The effects of dietary DNA (sodium salt), extracted from chum salmon milt, on memory, age-related changes and fertility were investigated in the P-8 strain of senescence-accelerated mice (SAMP8). Mice were fed a diet without (control group) or with 0.1% DNA for 10 months (DNA group). In passive and active avoidance tests, the age-induced deterioration of memory was reduced significantly in the DNA group (p<0.05). To evaluate the degree of senescence, we scored physical changes of aging, including movement and appearance, and found that these changes were significantly lower in the DNA group (p<0.05). Moreover, concentration and mobility of spermatozoa were significantly enhanced (p<0.05), and the activities of superoxide dismutase and catalase in the liver were significantly higher in the DNA group (p<0.05). It has been suggested that these changes in aging and fertility are due to the fact that dietary DNA enhances antioxidant activity, indicating that dietary DNA may be effective in preventing the deterioration of memory with aging and age-related physical changes in the body.

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Sensory analysis is a tool that uses the human senses to evaluate perceived sensory properties of food products. Effective sensory analysis is mostly dependent on a competent descriptive group of panelists. Therefore, it is important to establish the methodology for selection of panelist who will give reliable sensory analysis of food products. We herein report the development of criteria for selecting competent descriptive panelists who are specialized in evaluating soy sauce and its related products. We examined 47 candidates from outside the organization for suitability as descriptive panelists by implementing various sensory tests. We first obtained background information of the candidates, including age, gender, medical record, and eating, drinking and/or smoking habits, as well as the presence of any special food allergies. We then subjected them to a series of specific sensory tests to examine their abilities in recognizing basic tastes, discriminating odors, and describing perception in words. In addition, we determined the level of interest and motivation of each candidate toward foods and this work through interviews. Through optimizing the procedures and conditions of the taste-matching test, the odor discrimination test of soy sauce, and the descriptive test of diluted wine or Japanese noodle dipping sauce, we could determine who would be a good panelist for evaluating soy sauce. These tests indicated 5 out of the 47 candidates to be suitable panelists. This study is the first to report a successful screening process for selection of a competent panel that is specialized in evaluating soy sauce.

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To evaluate the safety of drinks containing the aqueous extract Kothala-himbutu (Salacia reticulata WIGHT), we conducted a double-blind study on the overdose of Kothala-himbutu over a 4-week period. A total of 54 subjects either healthy (n=27) or with borderline blood glucose levels and mild type 2 diabetes (n=27) were randomly assigned to untreated (placebo) or treated groups. Subjects consumed a drink containing the placebo or Kothala-himbutu extract powder (450mg, 3 times the recommended amount) at breakfast and dinner every day. Continuous over doses of the drink containing Kothala-himbutu extract led to no significant clinical changes or adverse effects, such as hypoglycemia and gastrointestinal symptoms during the entire study period. However, the subjects with borderline blood glucose levels and mild type 2 diabetes in the treated group showed significant changes in the amount of HbA_1c and glycoalbumin during the 4-week period compared to those of the placebo group (p<0.05). In conclusion, this study suggests that continuous consumption of Kothala-himbutu extract is safe in healthy adults as well as those with borderline blood glucose levels and mild type 2 diabetes.

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Polished rice was put into polyethylene bags, packed with Kraft paper, and preserved at four different temperatures : 10, -20, -40, and -60°C. Changes in quality of rice stored under these temperatures was tested at 2, 4, and 6 months using raw and cooked samples. In the case of preservation at 10°C, raw rice showed a decline in the rate of water absorption, higher hardness of the rice granules after water absorption, and a drastic decrease in the amount of reduced sugar eluted to the soaking solution, indicating deterioration in quality. Deterioration in quality was less at lower preservation temperatures ; rice preserved at -60°C showed little deterioration. Cooked rice samples using rice preserved at 10°C had higher hardness and lower adhesiveness, while cooked rice samples using rice preserved at -60°C showed little change in quality. After preservation for 6 months, cooked rice using the rice preserved at -60°C was significantly preferable to that using rice preserved at 10°C.

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The objective of this study was to compare the quality of spinach grown by commercial organic and conventional farming methods in autumn and winter. The parameters that determine spinach quality, including ascorbic acid, β-carotene, nitrate, oxalate, sucrose, and free amino acids, were analyzed from 16 pairs of organic and conventional farms. Based fresh and dry weights, organically produced spinach was found to contain significantly lower β-carotene content but had significantly higher glutamine, proline and total free amino acid contents. β-carotene content was correlated with total nitrogen and nitrate contents in spinach, indicating that the significant difference in β-carotene content between organically and conventionally grown spinach was due to differences in nitrogen level in the soil. However, the difference in free amino acid was not significant.

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The effect of Porphyra extract (PE), containing 10.5% of γ-aminobutyric acid (GABA), on blood pressure in spontaneously hypertensive rats (SHRs) was examined. Single dose oral administration of PE (2mg/kg of rat weight) in SHRs showed a significant reduction in systolic blood pressure. SHRs fed a diet containing PE at the level of 0.003% for 35 days showed a significantly lowered blood pressure compared to the control group. Moreover, these same rats showed lowered angiotensin I-converting enzyme (ACE) activities in the serum, abdominal aorta and lung. On the other hand, the concentration of PE producing 50% inhibition of rabbit lung ACE activity in vitro was 0.47mg/ml. These results suggest that the lowered blood pressure of SHRs was due to GABA and some ACE inhibitory components in PE.

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The Japanese phrase, shajuku-eki (SE), refers to the filtrate obtained after re-boiling azuki bean for 90 min to remove the astringency-component during the manufacturing of azuki paste. Currently, SE is discarded as a by-product of azuki paste following treatment with microbes. Here, we investigated the stachyose content in SE and methods to recovery stachyose for the purpose of effectively reusing SE. We found that the stachyose content in SE was 25.9-49.3% that of the total stachyose content in azuki beans of 5 cultivars, and that the carbonation process showed the highest recovery rate of stachyose (70.6-80.0% yield) with 75.5-80.5% decolorization. These results indicate that effective re-utilization of SE may be possible.

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We investigated the effect of dietary DNA (sodium salt), extracted from chum salmon milt, on the endurance running capacity in mice. Mice were fed the same diet without (control group) or with 0.1% (w/w) DNA (DNA group) for 12 weeks and exercised on a treadmill at weeks 6 and 12. Our results showed that mice ran a significantly longer distance in the DNA group than the control group (p<0.05). Moreover, the glycogen level in the femoral muscle and the glucose level in the plasma were significantly higher in the DNA group (p<0.05). These results suggest that dietary DNA activates glucose metabolism and consequently enhances the endurance running capacity in mice.

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[in Japanese]

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