The palatability and physicochemical properties of milled rice produced at different locations in the Kyushu and Chugoku Districts were studied, using the highly palatable rice cultivar Hinohikari. The rice produced at 10 locations was highly palatable, and comparable to the rice cultivar Koshihikari, which was used as the standard. On the other hand, differences in palatability with location and the production year, and the interaction between location and production year were significant. The standard partial regression coefficients against palatability were the highest for taste among the sensory attributes. The palatability was negatively and significantly correlated with the hardness/adhesion ratio (H/-H ratio) of cooked rice in terms of textural characteristics, but was not correlated with the content of protein or amylose. Thus, the palatability of rice produced at each location was strongly affected by the taste and the H/-H ratio of the cooked rice. These results show that we can efficiently evaluate the palatability of rice produced at different locations by measuring the H/-H ratio after cooking.

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Umezu (plum vinegar) is an exudate obtained from the pickled fruit of Prunus mume Sieb. et Zucc., Rosaceae. Umezu was passed through a Diaion HP20 adsorption column, which was washed with distilled water to remove salt and eluted with 90% ethanol solution. The eluate was concentrated in vacuo to obtain Umezu extract. In this study, the effects of dietary Umezu extract on blood pressure and lipid metabolism were examined in stroke-prone spontaneously hypertensive rats (SHRSP) fed a high-cholesterol diet. The high-cholesterol diet (control diet) was prepared by addition of 1% cholesterol and 0.25% sodium cholate to the purified diet according to the AIN-93G formula. Two groups of 6 male rats were used at the age of 6 weeks. One was fed the control diet and the other was fed the experimental diet (control diet containing 1% Umezu extract) for 6 weeks with free access to the diet and water. Elevation of systolic blood pressure was significantly suppressed with time in the experimental group (p<0.001 by two-way repeated ANOVA) after 4 weeks on the diet. Serum lipid hydroperoxide concentration was significantly decreased in the experimental group (p<0.05). Moreover, hepatic triglyceride content in the experimental group was significantly lower than that in the control group (p<0.05). These results indicate that Umezu extract suppresses the elevation of blood pressure, and the increases in serum lipid hydroperoxide concentration and hepatic triglyceride accumulation in SHRSP fed a high-cholesterol diet.

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An ezoukogi root extract (EUE) was examined for its physiological effects in various screening systems using experimental animals. No abnormalities could be observed in a safety evaluation involving single oral administration of 6, 000mg/kg and two-week multiple administration at doses up to 3, 000mg/kg/day. EUE was examined for its protective effects against vitamin C deficiency in a guinea pig model. The animals were given vitamin C-deficient feed alone (control group) or vitamin C-deficient feed containing EUE at a concentration of 0.25% (test group) for 30 days. On day 28, the animals were shaved to remove the hair in an area of the back. The skin at a site within the shaved area was exposed to UV light. On day 30, the skin collected from the UV-exposed site was analyzed for its lipid peroxide content, and the non-UV-exposed skin was examined for its collagen content. The analytical results indicated that consumption of EUE not only suppressed lipid peroxide formation, but also inhibited the decrease in collagen content. The rats were immersed in cold water for 15min, and the time required for recovery of their body temperature was measured. The recovery time was significantly shorter in the group treated with EUE at 500mg/kg for 2 weeks than in the control group, suggesting that EUE improves peripheral blood circulation. Mice were used to measure swimming time in the forcible swimming load test. The swimming time was significantly longer in the group treated with EUE at 500mg/kg for 2 weeks than in the control group, suggesting that EUE has an anti-fatigue effect. From the above results, it is estimated that EUE has a suppressive effect on lipid peroxide formation in the skin, a protective effect against collagen loss, an improving effect on peripheral blood circulation, and an anti-fatigue effect.

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Hypothalamic neuronal histamine is a derivative of histidine. It has been shown to both suppress food intake and accelerate lipolysis as a target of leptin in rats. The present study aimed to examine whether or not histidine intake affects feeding suppression, lipolysis and the serum leptin concentration in moderately obese women. The subjects were 118 moderately obese females (mean BMI 29.2±0.3kg/m², mean age 46.9±0.8 years) who participated in a weight reduction program for three months. Blood sampling and a nutritional survey were carried out, and the subjects' weight was measured before and after weight loss. A negative correlation was shown between energy intake and histidine/protein intake after weight loss. This relationship demonstrated statistical significance after controlling for the serum leptin concentration. A significantly positive correlation was shown between histidine/protein intake and the free fatty acid level. In conclusion, these data suggest that histidine intake suppressed food intake and accelerated lipolysis in these moderately obese women. Therefore histidine may be an effective amino acid for preventing or ameliorating moderate obesity.

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The inhibitory effects of ukogi (Acanthopanax sieboldianus) leaves on postprandial blood glucose elevation were investigated using sugar tolerance tests in rats. Ukogi leaves significantly suppressed the increase in blood glucose level after oral administration of maltose or glucose (p<0.05). As an in vitro study had shown that ukogi leaves inhibited maltase activity, we then investigated which components in a methanol extract of ukogi leaves were effective. Water eluants and 1% NH₃/MeOH eluants markedly inhibited the maltase activity. These results suggest that ukogi leaves suppress postprandial hyperglycemia by inhibiting maltase activity and glucose absorption, and that the inhibition of maltase activity might be due to the polyphenol components in ukogi leaves.

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The mucosal surface of the intestine comprises epithelial monolayer cells that are critical for the absorption of nutrients and defense against a variety of organisms or toxins. Aging epithelial cells must be rapidly replaced by younger cells for the maintenance of normal function. However, details of the underlying mechanism governing the rapid turnover of intestinal epithelial cells have remained largely unknown. Recently, we found a novel enzyme, designated membrane-type serine protease 1 (MT-SP 1), and suggested that it is a key molecule for control of intestinal epithelial turnover under physiological conditions. Moreover, we found that pancreatic secretory trypsin inhibitor (PSTI) inhibits granzyme A (GrA), which is likely to induce apoptosis of abnormal intestinal epithelial cells. These results suggest that intestinal epithelial cells themselves produce proteases such as MT-SP 1 that can regulate turnover of the intestinal epithelium, and that the pathological cell turnover mediated at least partly by GrA can be controlled selectively with substances such as PSTI.

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Dietary protein affects not only the metabolism of cholesterol, but also that of linoleic acid and triglyceride. Soy protein, as compared with casein, reduced the conversion of linoleic acid to arachidonic acid, and hence the production of eicosanoids, in rats. One of the mechanisms of the soy protein-dependent decrease of linoleic acid desaturation was considered to be a homeostatic response that compensates for an increase of hepatic microsomal membrane fluidity, caused by a decrease of the microsomal cholesterol/phospholipid ratio. Also, the protein-dependent effect could be at least due to aspects of amino acid composition, such as arginine content. On the other hand, dietary soy protein, as compared with casein, reduced the serum and liver triglyceride concentration and white adipose tissue weight in rats. Also dietary soy protein increased hepatic fatty acid β-oxidation. Recently, it has been shown that dietary conjugated linoleic acid (CLA) reduces adipose tissue weight. It can be considered that the body fat-reducing effect of dietary CLA becomes more significant in combination with soy protein than with casein.

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