We analyzed the cooked flavor of seasoning soy sauce (SS) and identified some odorants that contribute to the Koku taste (mouthfulness and continuity of the flavor) of SS by sensory evaluation. Two kinds of SS were prepared from bonito with or without sea tangle. The former (SS1) had a strong Koku taste and the latter (SS2) had a weak Koku taste. Volatile compounds of these SS were extracted by SDE and analyzed by GC and GC-MS. The FD factor of each compound was calculated by GC-O/AEDA (aroma extract dilution analysis). 10 ppt to 1 ppm of the volatile compounds with a relatively high FD factor were added to the solution containing 0.5 % NaCl and 0.3 % sodium glutamate, and then the strength of Koku taste was investigated by sensory evaluation with or without the use of a nose clip. In SS, 73 kinds of compounds were identified by the SDE method. Many volatile compounds had roasted, smoky, sour-like, and sweet aromas. 2,5-Dimethylpyrazine, which is known as an enhancer of Koku taste, was identified in SS1 and SS2. Thirty-eight kinds of compounds, including 2,5-dimethylpyrazine, were recognized to be significantly different between SS1 and SS2 in FD levels and quantitative amounts. Of these, we evaluated the contribution of 11 kinds of compounds (1-butanol, 3-methylbutanol, 1-hexanol, 1-octen-3-ol, 2-ethylhexanol, 1-heptanal, 1-octanal, furfural, benzaldehyde, 2-acethylfuran, and 2,5-dimethylpyrazine) to Koku taste. 2-Acetylfuran, 2-ethylhexanol, 1-octen-3-ol and 2,5-dimethylpyrazine were found to contribute to Koku taste. In addition, with the use of a nose clip, there were no significant differences detected in Koku taste between the control solutions with and without these compounds, indicating that these aromas contributed to Koku taste.

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We investigated the effect of lactic fermented soymilk in improving hepatic lipid metabolism in rats fed a high fat and high cholesterol diet. Male Sprague-Dawley rats, aged 7 weeks, were fed a very high lipid diet (VC diet) or moderately high lipid diet (MC diet) for 5 weeks. The VC diet contained 30 % triacylglycerol (TG) and 0.5 % cholesterol ; for VF diet (very high lipid diet with fermented soymilk), 25.0 % of the VC diet was replaced with fermented soymilk. The MC diet contained 15 % TG and 0.125 % cholesterol ; for MF diet (moderately high lipid diet with fermented soymilk), 22.2 % of the MC diet was replaced with fermented soymilk. Only hepatic crude lipid and cholesterol contents were significantly suppressed in the VF group, whereas plasma total cholesterol (TC) and TG levels, as well as hepatic crude lipid, cholesterol and TG contents were significantly suppressed in the MF group. There was no down-regulation of hepatic lipid metabolism-related gene expression in the VF group ; in contrast, the expression of FAS was down-regulated in the MF group. These results suggested that the effect of fermented soymilk in improving lipid metabolism was small in rats fed the VC diet, likely due to reduced hepatic metabolic function caused by lipid overloading, whereas ingestion of fermented soymilk effectively suppressed the accumulation of hepatic lipid and the elevation of plasma lipid levels in rats fed a MC diet.

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The flower of the chrysanthemum plant Shiranui Himekiku has been used as a folk medicine for a variety of diseases including cancer, and cytotoxic effects in some cancer lines have been reported. However, little is known about the anti-cancer activity of the leaf extract and its active compounds. Therefore, to clarify the anti-cancer activity of Shiranui Himekiku leaf and flower, the anti-proliferative effects of the extracts on human cancer cells were examined. Both leaf and flower water extracts dose-dependently suppressed the proliferation of the human breast cancer cell line MCF-7 at concentrations > 25 μg/ml. Furthermore, the anti-proliferative effect in MCF-7 is more than four times that in normal human dermal fibroblast cells. When heated at 100°C for 30 minutes, the proliferation inhibitory activity of the flower extract was unchanged. In contrast, under identical conditions, the activity of the leaf extract was lost. The extracts were separated into two fractions ; one with a molecular weight (MW) > 10 000 (high molecular weight fraction) (HMW) and the other with a MW < 10 000 (low molecular weight fraction) (LMW). A significant proliferation inhibitory effect can be seen in the LMW fraction of both extracts, but the HMW fraction of the leaf extract also slightly inhibits cell growth. Both polyphenols and non-polyphenols are candidate active compounds because the anti-cancer effect was seen in the polyphenol- and non-polyphenol-fractions. These results suggest that the extracts contain several types of anti-cancer components and that both leaves and flowers can be useful.

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The present study confirmed the presence of a fluorescent component (Ex490 nm/Em520 nm) in pu-erh tea using a three-dimensional fluorescence spectrophotometer. This component was detected at small quantities in other teas such as green tea, oolong tea and black tea. The compound was fractionated from hot-water extracts of pu-erh tea using liquid-liquid distribution and column chromatography methods. Fluorescence analysis and element assay suggested that the compound was a highly polar and high-molecular-weight complex, similar to humic substances. The compound is stable and the dose-response curve on fluorescence intensity showed linearity for quantitative estimation. In addition, teas with longer aging periods and higher prices showed stronger intensity. These results suggest that measurement of fluorescence in this region is useful for quality determination of pu-erh tea and in distinguishing it from other fermented teas.

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Simultaneous determination of ascorbate and dehydroascorbate by high-performance liquid chromatography was examined. Based on the method of Yasui et al. (1991), the most suitable column for good separation was selected from various ODS columns and separation modes not described in the original report. Using the Imtakt Unison UK-C18 (3 μm, 4.6 mm × 150 mm) column, with 2 mM HClO₄ at 1.0 ml/min as an eluent, 100 mM NaOH and 100 mM NaBH₄ at 0.5 ml/min as a post-column reaction, and UV detection at 300 nm, the separation of the peaks was greatly improved when compared with the original method, and analysis time was shortened.

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Translational viscometers, such as back extrusion devices, are simple because they do not include a rotary drive. In the back extrusion method, viscosity is obtained from the force-time curve drawn based on the flow of the annulus between the plunger and the cup in the concentric cylinder. After measurement, it is necessary to wipe off any residual sample adhering to the plunger. If this wiping is not performed, measurement accuracy decreases. Therefore, it is difficult to perform consecutive measurements of identical samples using the back extrusion method. In this paper, we propose an improved back extrusion method, designated the short back extrusion method, in order to enable consecutive measurements of high-viscosity samples. Under this proposed method, the plunger is immersed into the sample prior to measurement. The plunger is then pushed slightly to force the sample into the upper part of the annulus, and viscosity is obtained from the stress-time curve. Using a standard viscosity sample, we compared the measurement accuracies of the proposed method and the back extrusion method. The comparison showed that the proposed method was more accurate than the back extrusion method. In addition, we confirmed that consecutive measurements of high-viscosity Newtonian fluids were possible using the proposed short back extrusion method.

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We kneaded third-crop green tea and loquat leaves and prepared them by a firing process in order to manufacture a new fermented tea mix. Sensory testing was carried out and aromatic compounds were measured during the firing stage in order to investigate the effects of temperature and time on the tea product. The firing process did not alter the contents of the major aromatic chemicals in the tea mix. On the other hand, levels of (E,E)-2,4-heptadienal, an unfavorable aromatic chemical found in low-grade tea leaves, decreased with increases in both temperature and time. Aromatic compounds increased only when firing was carried out at higher temperatures and for longer periods. The firing process does not typically enhance favorable flavors of third-crop teas. However, this study demonstrated that firing can enhance heat-induced aromatic compounds, thereby making it suitable for first-crop green tea processing.

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