Two series of experiments were performed on healthy human female volunteers to examine the acute and chronic effects of Oolong tea on plasma lipid levels and post-heparin plasma lipoprotein lipase activity. In one experiment, subjects either in a fasting state or fed a high-fat meal were given a single dose of 3- or 5-fold concentrated Oolong tea. Blood samples were collected from the subjects immediately before, and at 30, 60, 120 and 180 min after tea intake. Oolong tea had no effect on the plasma levels of total cholesterol, HDL cholesterol, triglyceride or phospholipid. However, the free fatty acid level was elevated rapidly with time after Oolong tea intake. The differences were significant compared with the control for both the fasting and fed states. In the other experiment in which the chronic effects of Oolong tea were studied, the subjects drank 7 cups of normal-concentration Oolong tea per day for 6 weeks. In subjects given Oolong tea for 6 weeks, plasma levels of triglyceride and phospholipid were decreased significantly. The plasma total cholesterol level was not affected, but the ratio of HDL cholesterol to total cholesterol improved in the final week. No significant effect on hepatic triglyceride lipase activity could be detected, but lipoprotein lipase activity was increased significantly.

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It is well known that the incidence of liver tumorigenesis in gnotobiotic C3H/He male mice associated with a bacterial combination of Escherichia coli, Enterococcus faecalis and Clostridium parputrificum is markedly higher than in germ-free C3H/He male mice. It is also suggested that this promoting effect is closely related to the bacterial composition of the intestinal microflora. We examined the effect of addition of Bifidobacterium longum SBT 2928 (BL2928) to the above bacterial combination on the liver tumorigenesis and various types of bacterial metabolism potentially related to carcinogenesis risk. The incidence of liver tumors was reduced by addition of BL2928 to the bacterial combination, but no significant changes were observed in fecal β-glucuronidase, nitroreductase or azoreductase activity, or in the fecal concentrations of phenols and indoles of gnotobiotic C3H/He male mice. These results suggest that at least the fecal concentration of phenols is not related to the inhibitory effect of BL2928 on liver tumorigenesis in gnotobiotic C3H/He male mice.

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The effects of exercise and fasting on the fatty acid composition of epididymal fat tissue, serum energy substrate levels, liver glycogen levels and liver O2 consumption were examined in mice fed animal oil or vegetable oil. Male ICR mice were divided into four groups, which were given beef oil (Beef), corn oil (Corn) olive oil (Olive) or coconut oil (Coconut), and were kept individually on the experimental diets for about 60 days. The fatty acid composition of epididymal fat tissue in other groups except for Coconut reflected directly the fatty acid composition of each dietary fat. In the epididymal fat tissue of all groups, fatty acid compositions were not changed by exercise or fasting. Serum glucose levels in all groups showed a decrease or a decreasing tendency due to fasting or exercise. Serum free fatty acid levels in all groups were increased significantly by fasting or exercise. In particular, the degree of enhancement by Olive and Beef was greater than those in the other groups. Liver glycogen levels after fasting and exercise in Olive or after fasting in Beef remained unchanged. Liver tissue O2 consumption was higher in Olive, Beef and Corn than in Coconut. Considering the above findings, the present study suggests that olive or beef oil in the diet may play an important role in effective utilization of free fatty acid as an energy source and in slowing the rate of glycogen depletion during exercise of fasting.

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Effects of Spirulina on serum lipid components and glucose tolerance in rats were studied. Experiment diets were prepared with 20% Spirulina water-soluble fraction (SS), with 20% Spirulina waterinsoluble fraction (SI) or with 18% casein (CN). Each group of 8 male Sprague-Dawley rats were fed with SS, SI and CN diets for 4 weeks in individual cages. Fasting serum glucose levels were measured on the 7th and 28th days, and glucose tolerance on the 28th day. The nitrogen balance was also examined during the last 3 days. Total-cholesterol, HDL-cholesterol and triglycerides in serum were measured on the 28th day when the rats were sacrificed. No effect was observed on either growth or feed efficiency among all groups. The highest ratio of HDL-cholesterol to other cholesterols and the low fasting serum glucose levels were observed in the SS group. In the glucose tolerance test, the elevation of glucose seemed to be more suppressed in the SI group than in the SS group.

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Two experiments were carried out to examine the additional effect of a fiber mixture (FM) containing a ratio of 66.7% hemicellulose, 8.9% chitosan, 2.2% alginic acid and 22.2% isomalto-oligosaccharide. In Experiment 1, the rats were fed a fiber-free diet supplemented with 1%, 3%, 5% and 10% FM for 4 weeks and the dietary fiber content in FM was 67%. In Experiment 2, the rats were fed 12 kinds of diet for 9 days; that was the experimental diet of the content with 1%, 5%, 10% and 15% FM of each diet with 5%, 15% and 30% lard. A digestion test using the total collection method was carried out. The heat of combustion of the diet and feces was determined, and the apparent digestible energy in each diet was calculated. Transit time and fecal weight (g/100 fecal pellets) were investigated to understand the condition of fecal excretion. An increase in the intake of FM resulted in a greater energy loss from feces, and the apparent digestible energy content of the diet varied from 460 to 419kcal/100g (Exp. 1), and from 544 to 379 kcal/100g (Exp. 2). Transit time was significantly reduced in the diet supplemented with 5-10% FM (p<0.05), and the fecal weight was significantly increased by addition of 5% FM at all lard levels (Exp. 2). These studies demonstrate that the desirable ratio of apparent digestible energy to dietary fiber in the diet ranges from 76 to 135 kcal/g under the present conditions of fecal excretion.

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The effects of oligosaccharides and lactose on utilization of calcium, magnesium, phosphorus and iron were examined in weanling male Wistar rats. The rats were fed a casein-based diet supplemented with galactooligosaccharides (GO), fructooligosaccharides (FO), lactose (LO) or corn starch (control) for 30 or 180 days. Rats fed the LO or FO diet for 30 days absorbed calcium more efficiently than those on the control diet, and showed higher retention of calcium. Rats fed the LO, GO or FO diet for 30 or 180 days absorbed magnesium efficiently. For phosphorus, only rats fed the FO diet showed higher retention during 30 days of feeding. For iron, rats fed the GO diet for 30 days showed less absorption than those on the control diet. Rats fed GO or FO showed a lower pH value of the cecum content during 30 days of feeding, but a slightly higher pH than rats fed the control diet for 180 days.

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The amounts of dietary fiber in 47 species of mushroom were determined by the enzymatic-gravimetric and neutral detergent methods as total dietary fiber (TDF) and neutral detergent fiber (NDF), respectively. TDF includes water-soluble and -insoluble dietary fiber, whereas NDF includes only waterinsoluble dietary fiber. Therefore, the amount of TDF is theoretically higher than that of NDF. However, in 19 species of mushroom, the amount of TDF was lower than that of NDF. The value of TDF was corrected by subtracting the amouat of protein (NV×6.25) in the TDF fraction, which was determined by the enzymatic-gravimetric method. It is widely known that mushrooms contain chitin, which is a type of dietary fiber containing nitrogen. A highly accurate value of TDF can be obtained by chitin correction. The average amounts of chitin in the samples and the apparent protein in TDF fractions were 6.16±2.64and 9.36±3.50, respectively (% on a dry wt. basis±S.D). The amount of true protein corrected for chitin was calculated by subtracting the amount of N in the chitin fraction from the amount of N in the TDF fraction, and then multiplying by 6.25. The average amount of corrected proteinwas 6.70±3.03%. Although the average content of TDF before correction for chitin was 40.68±17.36%, the tme value of TDF after this correction was 43.33±16.71%. Therefore, the amounts of corrected TDF were higher than the amount of NDF in all of the samples examined.

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A high-performance liquid chromatographic method was developed to estimate the amount of taurine in foods. A Shodex Ionpak c-811, an adsorption-distribution-type column, was chosen in combination with 3mM perchloric acid as the mobile phase. The eluted taurine was derivatized with O-phthalaldehyde-2-mercaptoethanol reagent and measured at an absorbance at 350nm instead of the fluorescence intensity. Using this method, it was possible to isolate and estimate the amount of taurine from other coexisting amino acids. The linear relationship was obtained between the concentration of taurine and absorbance over a concentration range of 1.0-100.0nmol and the recoveries were 98.1±2.0% by the internal standard methods. The specificity, reproducibility and sensitivity of this method for taurine were good enough for food applications. Examples of the taurine content in various fish and shellfish, as determined by this method, are also presented.

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Fatty acid composition and tocopherol content were measured in seasonings and spices, i. e., 6 brands of miso, 3 mayonnaise, 9 dressings, 7 flavor seasonings, 6 consommes, 2 hash and 6 curry rouxes, 13 prepared seasoning mixes and 3 soup mixes. Mayonnaises and dressings were found to be made of vegetable oils, such as corn, rice bran, soy bean and rapeseed oils. However, others were composed of hydrogenated vegetable and animal oils, so that the t-18: 1 showed a range of 3.9-39.9%. The influence of t-18: 1 seemed to be negligible, because only small amounts of the seasonings and spices analyzed would be used. Tocopherols were detected in all samples, and there were no problems in their quality or quantity as antioxidants.

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