Ryoko Shimada

This study obtains data to develop methods for advertising the rock oyster (Crassostrea nippona) as a regional branded food by investigating the degree of recognition of the characteristics of the rock oyster, the Pacific oyster (C. gigas), and the common oyster by young people living in oyster-producing regions. The survey was conducted in the production regions of Japan, namely, Nagasaki, Hyogo, Miyagi, and Hiroshima prefectures. The participants were university students who would become future consumers of the rock oyster. Approximately 40% of the participants recognized the rock oyster; furthermore, less than 20% of them had consumed it. Thus, most participants did not recognize and/or had never consumed the rock oyster. Furthermore, the season of the rock oyster was identified to a lesser degree than that of the Pacific oyster. Most participants could not identify the production region of the rock oyster. The most common perceptions of nutrients and dishes associated with oysters were minerals and fried and grilled dishes, respectively. These findings are useful as a basis for developing methods to advertise the rock oyster as a regional branded food.

Resistant starch (RS) displays similar physiological properties as dietary fiber. In this study, bread making properties and sensory acceptability of bread replaced with RS type 4 (RS-4, chemically modified starch) were evaluated. Distarch phosphate potato, rice and tapioca starch, phosphated distarch phosphate sweet potato and wheat starch were used as RS-4 source. RS-4 replaced 20% (w/w) of wheat flour, and each of the breads were thereby considered RS-4 breads. Bread without RS-4 was called Control bread. RS-4 breads were shown to have less specific volume than Control bread. Hardness of RS-4 breads was higher than that of Control bread. It was observed by SEM that RS-4 were not gelatinized in bread. However, RS-4 breads obtained overall acceptability similar to Control bread in sensory evaluation.

Resistant starch (RS) is a form of starch that is not digested and absorbed in the stomach and small intestine, but passes to the large intestine. RS displays similar physiological properties to dietary fiber. In this study, bread making properties and sensory acceptability of bread replaced with RS type 4 (RS-4, chemically modified starch) were evaluated. Hydroxypropylated tapioca starch (HPTS) and cross-linked phosphate tapioca starch (CLTS) were used as RS-4 sources. RS-4 (20％) was used to replace (w/w) wheat flour, and the resulting breads were called RS-4 breads. Bread without RS-4 was called WF-bread. RS-4 breads showed lower fermentation volumes on fermentation tests and specific volume of bread than WF-bread. Hardness of RS-4 breads was higher than that of WF bread. The color of RS-4 breads was different from WF bread. However, RS-4 breads obtained overall acceptability similar to WF bread in sensory evaluation.

We examined whether soybean (SB) and soy protein isolate (SPI) can prevent the betaine-induced elevation of plasma cholesterol as well as maintain the betaine-induced reduction of plasma Hcy concentration. Rats were fed casein-, SB-, or SPI-based diet with or without betaine SPI-based diet with betaine containing soybean fiber (SF) or soy lecithin (SL) or the combination of SF and SL. Plasma Hcy concentration was decreased by feeding betaine to rats fed the casein-, SB-, and SPI-based diets. Betaine-induced elevation of plasma cholesterol was decreased by feeding the SB-based diet compared with the casein-based diet, but was not decreased by feeding the SPI-based diet. In rats fed the SPI-based diet, the increased concentration of plasma cholesterol by betaine feeding was not prevented by independent addition of SL or SF, but was prevented by a combination of SL and SF, and was associated with increased fecal excretion of bile acids.

In the present study, the effects of Euglena and paramylon on hyperglycemia were examined in Otsuka Long-Evans Tokushima fatty (OLETF; type 2 diabetes mellitus model) rats. OLETF rats were fed an AIN-93 M diet containing cellulose, Euglena, or paramylon for 10 weeks. Long-Evans Tokushima Otsuka (LETO) rats were used as nondiabetic controls. An oral glucose-tolerance test (OGTT) was performed at 0 and 10 weeks. OLETF control rats were obese because of bulimia and showed abdominal fat accumulation and hyperglycemia. Euglena supplementation improved hyperglycemia and decreased food intake, body weight gain, and abdominal fat. However, there were no changes in the paramylon-supplemented group compared to the OLETF control group. Triglyceride concentrations in the serum and liver were lower in Euglena-supplemented rats than in OLETF control rats. There was a correlation between hepatic triglyceride concentration and the area under the curve (AUC) of OGTT at 10 weeks. This suggests that the improvement in glycemic control in the Euglena-supplemented group may depend on substances other than paramylon present in Euglena.

Biotin is a water-soluble vitamin that functions as a cofactor for biotin-dependent carboxylases. The biochemical and physiological roles of biotin in brain regions have not yet been investigated sufficiently in vivo. Thus, in order to clarify the function of biotin in the brain, we herein examined biotin contents, biotinylated protein expression (e.g. holocarboxylases), and biotin-related gene expression in the brain of biotin-deficient rats. Three-week-old male Wistar rats were divided into a control group, biotin-deficient group, and pair-fed group. Rats were fed experimental diets from 3 wk old for 8 wk, and the cortex, hippocampus, striatum, hypothalamus, and cerebellum were then collected. In the biotin-deficient group, the maintenance of total biotin and holocarboxylases, increases in the bound form of biotin and biotinidase activity, and the expression of an unknown biotinylated protein were observed in the cortex. In other regions, total and free biotin contents decreased, holocarboxylase expression was maintained, and bound biotin and biotinidase activity remained unchanged. Biotin-related gene (pyruvate carboxylase, sodium-dependent multivitamin transporter, holocarboxylase synthetase, and biotinidase) expression in the cortex and hippocampus also remained unchanged among the dietary groups. These results suggest that biotin may be related to cortex functions by binding protein, and the effects of a biotin deficiency and the importance of biotin differ among the different brain regions.

To characterize a new function of the water-soluble vitamin, biotin, in reproduction and early growth in mammals, the effects of high dietary doses of biotin on early spermatogenesis were biochemically and histologically investigated in male rats. Weaned rats were fed a CE-2 (control) diet containing 0.00004% biotin, or a control diet supplemented with 0.01%, 0.1%, or 1.0% biotin. Pair-fed rats were fed a control diet that was equal in calories to the amount ingested by the 1.0% biotin group, because food intake was decreased in the 1.0% biotin group. Food intake and body weight gain were lower in the 1.0% biotin group than in the control group. The kidney, brain and testis weights were significantly lower in the 1.0% biotin group than in the pair-fed group after 6 weeks of feeding. The accumulation of biotin in the liver and testis increased in a dose-dependent manner. In the 1.0% biotin group, the number of mature sperm was markedly lower, that of sperm with morphologically abnormal heads, mainly consisting of round heads, had increased. In addition, the development of seminiferous tubules was inhibited, and few spermatogonia and no spermatocytes were histologically observed. These results demonstrated that the long-term intake of high-dose biotin inhibited spermatogenesis in young male rats.

In the present study, the effects of beta-glucans isolated from Euglena on the formation of preneoplastic aberrant crypt foci (ACF) in the colon were examined in mice. Mice were fed a semi-purified AIN-93M diet containing cellulose or the same diet but with the cellulose replaced with beta-glucans in the form of Euglena, paramylon, or amorphous paramylon, for 11 weeks. After consuming these dietary supplements for 8 days, half of the mice were intraperitoneally administered 1,2-dimethylhydrazine (DMH) at a dose of 20 mg kg(-1) body weight every week for 6 weeks. Among the DMH-treated groups, the paramylon- and amorphous paramylon-fed mice displayed a significantly lower number of ACF than the control group. Also, the liver weight of the paramylon group was markedly decreased compared with those of the control and Euglena groups, whereas the cecal content weight and fecal volume of the paramylon group were significantly increased. As for the levels of organic acids in the cecal contents, the paramylon group displayed significantly increased lactic acid levels compared with the control and Euglena groups. From these findings, although the mechanism of the ACF-inhibiting effects of paramylon remains unclear, it is considered that beta-glucans, such as paramylon and its isomer amorphous paramylon, have preventive effects against colon cancer and are more effective against the condition than Euglena.