We prepared zein microcapsules containing glutamine using a solvent evaporation method in reverse multiple emulsion. In the experiment, fatty acids were added to the shell material to give the shell hydrophobicity ; as a result, zein microcapsules containing glutamine were successfully prepared by the microencapsulation method adopted here. It was found possible to change the release rate of the core material by addition of fatty acids. Moreover, it was found that the addition of oleic acid resulted in the strongest hydrophobicity and that the use of palmitic acid had the greatest effect on the content of the core material.

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We attempted to microencapsulate hem iron particles by fatty acids to give functionality, such as masking black color and water resistance. In the experiment, lauric acid, myristic acid and palmitic acid were used as shell materials and methyl cellulose (MC) and casein sodium (CS) were used as dispersants. Multicore-type and monocore-type microcapsules were prepared by addition of MC and CS, respectively. Furthermore, by addition of CS, the microencapsulation efficiency, black color masking and water resistance were significantly improved.

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Japonica rice is currently used to manufacture breads and cakes, and there have been many studies of the texture and taste of these items, but the preparation and practical use of rice noodles, which are manufactured using a rolling process, have not yet become viable because rice does not contain gluten. Following preparation of Vietnamese rice noodles made from Indica rice, we established in a preliminary experiment a method of obtaining noodles of consistent quality by cooking at 65°C. We prepared Japonica rice noodles with addition of tapioca starch and soy milk in order to improve their texture and nutritional value, and we conducted mechanical measurements using a Rheoner and sensory evaluation tests. The flow behavior of the rice flour suspension was measured by viscometer. Enthalpies of gelatinization and changes of state for Indica and Japonica rice starch were measured by DSC and followed by optical microscope observation during heating. These measurements showed that Japonica sol had high viscosity and high thixotropy at 90°C. The thixotropy was decreased by addition of tapioca starch but increased by the addition of soy milk. An increase in Casson yield stress was also confirmed in all cases. Based on the properties examined by DSC and optical microscope observation, the gelatinization temperature of Japonica rice was around 60°C, which was lower than that of Indica rice by about 10°C. Although the cooked noodle made from Japonica rice was soft and sticky and received unfavorable evaluations, noodles with added tapioca starch and soy milk received favorable evaluations.

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This study was carried out to clarify the effects of Phellinus linteus fruit body (PL-F) or mycelia (PL-M) powder on gallstone formation in mice fed a cholesterol-cholate diet. Male ICR mice were fed diets containing 0.5% cholesterol and 0.25% Na-cholate for 21, 28 or 35 days. Animals fed with a cholesterol-cholate diet showed higher incidence of cholesterol gallstone formation than those fed with PL-F or PL-M powder diet, for 21 days test. Gallstone formation in mice was not further suppressed by extending the feeding period to 28 or 35 days. On the other hand, addition of PL-M to the diet caused significantly lower serum atherogenic index and liver total cholesterol (TC) levels than the PL-F or PL-M free diets. Fecal excretion of TC and bile acid (BA) were increased by PL-F or PL-M feeding. With each PL-F or PL-M diet, TC/BA ratio in the gall bladder was lower than that with the control diet. Hot water extract of the PL-M fractions were found to be the most effective in preventing the formation of gallstones in mice fed with cholesterol diets and this effect was almost equal to that of the whole PL-M powder.

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We measured the adhesiveness of chewing gum using a rheometer fitted with an acrylic resin plunger made from denture materials operated under uniform liner motion. In view of mastication, we adopted reasonable measurement conditions of moisture, temperature, and shear rates. Corresponding to the duration of the occlusal phase, we set a hold time of pressure bonding between the plunger and chewing gum. Lower adhesiveness was measured in conditions without hold time. On the contrary, marked adhesiveness was observed under the 0.1-s hold time. It was suggested that the hold time of pressure bonding had a strong effect on the adhesiveness of chewing gum.

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A fish sauce (CSS) was prepared from gutted chum salmon (Oncorhynchus keta) using barley koji and halo-tolerant microorganisms (HTM) Zygosaccharomyces rouxii, Candida versatilis and Tetragenococcus halophilus. During fermentation, chemical analysis was performed to determine the pH of the fish sauce mash (moromi). After fermentation, the optical density at 550nm and the chemical and extractable components of CSS were compared with those of Thai fish sauce (nampla) and soy sauce. The pH of CSS moromi fell rapidly early in the fermentation process, and the color of CSS was lighter than that of fish sauce prepared without using HTM. The ethanol content of CSS was higher than that of nampla, but lower than that of soy sauce. According to free amino acid analysis, contents of aspartic acid, glycine, lysine and leucine were higher in CSS than in nampla and soy sauce ; however, its lactic acid, acetic acid and pyroglutamic acid contents were lower. Sensory evaluation showed that CSS had a soy-sauce-like flavor and a less fishy odor than nampla.

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The physical and chemical properties of new varieties of rice with novel characteristics were measured and compared to those of control rice. Cooked grains of various types of new rice (low-amylose rice, high-amylose rice, ordinary rice, and waxy rice) were characterized based on quality assays such as amylose content, stickiness, mechanical properties and palatability. Because marked fluctuations were not detected in the results of these measurements over three crop years, the results are likely to be an accurate expression of the characteristics associated with each variety or cultivar. Analysis of the information acquired via a taste-sensing system showed that this system is a promising tool for evaluating the influence of various taste components upon the overall palatability of the cooked rice grains. Clarification of the characteristics of the sample rice grains may be achieved by principal component analysis based on the variables obtained by physical or chemical measurement.

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Physical and chemical properties of the “Yumehitachi” rice grains developed and produced in Ibaraki Prefecture were characterized and compared against control rice varieties, and the effectiveness of making “Koshihikari” and low amylose rice blends to improve palatability were evaluated. The results are summarized as follows : (1) Quality of “Yumehitachi” was characterized as a high-palatable rice based on the quality assays such as amylose and protein contents, whiteness, pasting properties, physical properties of cooked rice grains, scores of rice palatability “mido-value” by the Taste Analyzer, and “suihan-shokumi-value” by the Taste Analyzer for cooked rice, and “property” by the “Taste Sensing System”. (2) The results of tests on blends with “Yumehitachi” and “Koshihikari” against a high-quality blend “Rice A” was that the balance degree (-H1/H1) was lower, “mido-value” of cooked rice was at a similar level, and pasting properties such as breakdown were higher, and consistency was lower. This suggests that the “Yumehitachi” and “Koshihikari” blend is as suitable as “Rice A”. (3) The blending of “Yumehitachi” with low-amylose rice improved the physical properties of cooked rice such as softness, balance degree (-H1/H1), “suihan-shokumi-value” by the Taste Analyzer for cooked rice, and made it more resistant to retrogradation after cooking.

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Ovary lipids extracted from skipjack tuna (OLS) are rich in docosahexaenoic acid combined with phospholipids. When male Wistar rats were given OLS every day for 15 days, OLS gave a protective effect against acute stress. Gastric mucosal injury in OLS-fed rats exposed the water immersion restraint stress (27°C, 7hrs ; WIRS) was lower than that of the control rats exposed the WIRS alone. Then, oil was given to control rats with the same energy % of n-3 and n-6 fatty acids and in the same n-3 : n-6 fatty acid ratio as the OLS mixed oil. In general, the surplus secretion of corticosterone is one of the primary factors in gastric mucosal injury. However, the concentration of serum corticosterone in OLS-fed rats was the same as in the control rats.

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Comparing the food composition of dahlia tubers with those of inulin-rich foods such as Jerusalem artichoke, chicory and edible burdock, we found that dahlia tubers were a good source of inulin, a soluble dietary fiber. We investigated the feasibility of using dahlia tubers which have been discarded because they lack buds as a food source for inulin. Dahlia inulin was extracted and purified as follows : after draining the first hot-water extracts from sliced tubers, the tubers were ground by electric mixer, boiled, and subjected to filtration. The filtrate was decolorized and deodorized using activated charcoal and then concentrated by boiling. Inulin was precipitated by addition of 4 volumes of ethanol and subsequently refined using 80% ethanol for food use. The average purities of inulin before and after refining were 83.2% (n=16) and 97.9% (n=8). We confirmed the absence of atropine in hot-water extracts of dahlia tubers using Dragendorff reagent and HPLC methods. Based on data obtained from addition and recovery of atropine to purified inulin, we concluded that dahlia tubers and the purified inulin obtained in this experiment were free from atropine.

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The viscosity of melted cheese during processing was determined using a Rapid Visco Analyzer (RVA). Values for viscosity at the start of melting (MSV) and stable viscosity (SV), which were obtained from the viscosity profile, decreased as the ripening period of the cheese increased. Both MSV and SV values were found to be correlated with the soluble nitrogen content, regardless of cheese type, but neither value was found to be correlated with Ca content or pH. These results suggest that MSV and SV values obtained by RVA may be used as indicators for characterization of cheese as an ingredient for processed cheese.

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[in Japanese]

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