Organic acids such as fumaric, malic and lactic acids are produced by associative growth of fermentative microorganisms and contribute largely to flavor of fermented foods. In the present study, the effect of cultural conditions on the fumarate metabolism was tested for three strains of Lactobacillus delbrueckii possessing an ability in conversion of fumarate to L-malate, and an attempt was undertaken as preliminary studies for the flavor improvement of fumaric acid forming-mold starter foods in combination with lactic acid bacteria. These strains were incubated in the basal medium (glucose-yeast extract-peptone) containing 1% sodium fumarate at 34°C under stand and shaking cultures and the cell growth and organic acid compositions during the incubation were tested. The effects of medium compositions and inorganic salts on the fumarate metabolism were investigated as well. Fumarate consumptions and the uptake of glucose by three strains were activated by the addition of fumarate to the basal medium. L-Malate production decreased after 24 to 28hours incubation under the stand culture, whereas the production showed a tendency to increase until 48hours incubation under the shaking culture. However, the productive ratio of fumarate to L-malate was nearly same in both stand and shaking cultures. On the other hand, stimlatory effects on the cell growth of three strains were observed in fumarate-added basal medium supplemented with magnesium ions. Their fumarate-hydrolyzing abilities were also stimulated, although the abilities were inhibited in the presence of copper ions.

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The application tests of red bean (Honkintoki) extract prepared from the seed coat to food were studied. Red bean extract showed strong antioxidative activity and synergistic antioxidative effect with citric acid, but, did not showed with α-tocopherol. Red bean extract had also strong antioxidative activity and synergistic effect with citric acid in lard by AOM test. On the basis of these results, the application tests of red bean extract to biscuit, fried wheat flour chips and model juice containing β-carotene were done and antioxidative activity was evaluated. Red bean extract exhibited strong antioxidative activity and more stronger antioxidative effect with the addition of citric acid in biscuit. In fried wheat flour chips, red bean extract had antioxidative effect with the addition of citric acid, but, the effect was weak. In model juice containing β-carotene, red bean extract had strong inhibition effect of β-carotene degradation. From these results, red bean extract might be used for natural antioxidants to lipid containing food and juice.

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Extraction of protein from common buckwheat was in vestigated to improve low digestibility of buckwheat. Furthermore, the improvement of taste of tartary buckwheat was conducted by using a protein extraction procedure, in which the buckwheat protein mainly consisting of globulin was recovered by isoelectric precipitation. In this case, the extraction temperature influenced greatly on a yield of the protein. The protein extracted from tartary buckwheat had no bitter taste.

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Eating quality is the most important theme in recent rice studies. Many factors for evaluating eating quality of rice were found and standard methods based on their factors have been established. Rice of good eating quality usually shows characteristics as follows: low amylose, low protein; large breakdown in amylography; small iodine-starch values in cooking quality tests; and large balance values in texturometer characteristics. Rice samples of twenty-two varieties were examined in this study, which include non-waxy, intermediate and waxy of Indica and Japonica varieties. Judging from instrumental measurements, Koshihikari, Todorokiwase, Akitakomachi, and Sasanishiki showed values of good eating quality among fifteen non-waxy varieties. While, Variety C, Basmati, RD-7, Variety A showed poor eating quality, and Niigatawase, Hokuriku No.100, Calrose (US), Calrose (AUS), and RD-21 showed values of intermediate quality.

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The changes of vitamin C in black tea extract were examined under various pH and heat processing conditions. Contents of vitamin C, Brix and pH in commercial canned black tea drinks were determined. After addition of vitamin C to black tea extracts (25mg/100g and 40mg/100g), pHs of these extracts were adjusted to 5.50, 6.60, 6.50, respectively and then the extracts were heated at 115°C for 13 and 19min., 120°C for 4 and 6min. and 121°C for 15min. After heat processing, total vitamin C (TVC) contents of the extracts were remained 70-80%, and no differences were seen any the different pH and heat conditions. The black tea extracts with the addition of vitamin C were adjusted to pH 4.60 and heated under the above mentioned conditions, the retention ratio of TVC and L-ascorbic acid (AsA) in these extracts heated at 120°C showed higher than that of 115°C. Average contents of TVC in commercial canned black tea drinks were 14.9mg/100g. In canned straight tea drinks, average values of Brix and pH were 4.9 and 5.56, respectively. Brix of flavored tea drinks were higher and pHs of these were lower than those of straight tea drinks.

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The changes in cell wall polysaccharides constituents in relation to hardness in small size ume fruit and Koumezuke (brined small size ume fruit) were investigated. While small size ume fruit softened in texture during maturation, the cell wall polysaccharides contents reduced to half from 2937mg/100g to 1460mg/100g. At the same time, the content of the pectin fraction was increased 44.3-0.1%, and that of hemicellulose II and cellulose fractions were decreased, 17.4-11.9% and25.9-21.9%, respectively. Koumezuke, brined in the solution calcium hydroxide was added and had a hard texture, had a constantly larger content of the cell wall polysaccharides than the fruit brined only with NaCl. The decrease was observed in pectin and hemicellulose I fractions components, on the other hand, hemicellulose II and cellulose fractions components were increased. Furthermore, ash and Ca bound to crude cell wall were remarkably larger in Koumezuke, and in the pectin fraction of Koumezuke, AGA content was small and neutral sugar content was large. From these results, the maintenance of hardness of ume were only performed in case of brining with calcium hydroxide. This phenomena was supposed to be caused by the fortified cell wall with calcium hydroxide, and it was caused by the increasing of hemicellulose II and cellulose fractions tightly bound to the cell wall which was formed through an obstruction of resolve of HSP and its combining with other cell wall constituents.

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We investigated a method for depolymerization of alginate with the enzyme system of Flavobacterium multivolum. The enzyme exhibited the maximum activity at pH 7.0 and 50°C, and was stable in the pH range of 4 to 8 and at temperature up to 40°C. Enzyme activity was activated in the presence of around 0.1M of NaCl, KCl and MgCl₂ in reaction mixture. The enzyme decreased the viscosities of solutions of sodium, potassium and ammonium alginates, and solution of propylene glycol ester of alginate. The enzyme belonged to alginate lyase and degraded Na-alginate by an endo-wise manner. The time-course of change in viscosity on large scale reaction is almost the same as that of beaker scale reaction, and the clarification of alginate digest was possible by the treatment with active carbon. Actually, a 4.9kg of Na-alginate (M/G=1.04) was degraded with the enzyme system (32.3g of the enzyme powder with 31814 U) of F. multivolum at pH 6.8 and 45°C for 2.5 h. The viscosity of reaction mixture, thus obtained, was about 4 centipoises (3.5%, W/W).

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The leaves of Cinnamomum tamala were collected from the trees grown in Nepal and were steam distilled to obtain the volatile oil. The chemical composition of this volatile oil was examined by GC/MS method. The components in cinnamon leaf oil were constituted of linalool (54.66%), a-pinene (9.67%), p-cymene (6.43%), β-pinene (4.45%), limonene (2.64%) and sixteen minor components less than 2.0%. The percentage of cinnamaldehyde is only 1.16% and then eugenol was absent in this volatile oil. The experimental data were compared with the data of different cinnamon leaf oils which were received from literature survey.

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A method to quantitatively determine the oligosaccharides in a commercial soybean lecithin product by high-performance liquid chromatography (HPLC) was studied. The lecithin product was dispersed in chloroform/methanol/water (10/8/9, v/v) containing an internal standard, and a portion of the water phase was injected onto the anion exchange HPLC column. Oligosaccharides were selectively monitored by a fluorescence detector after a post-column chemical reaction with arginine. This method was highly sensitive (<0.1μg) and also applicable for the determination of saccharide content in soybeans. By this method, we demonstrated that the oligosaccharides in the product were changed into fluorometrically undetectable components by a browning reaction, and that monosaccharides of soybean were not contained in the product.

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The composition of anthocyanin pigments in aromatic red rice (RP) and its wine (WP) was mainly determined by HPLC analysis. The WP was constituted of about seven cyanidin-or peonidin-based anthocyanins as were the pigments of RP. Based on the results of the mixture test with standard pigments, all anthocyanins in WP, except the fifth one eluted, could be identified as cyanidin 3, 5-diglucoside, 3-sophoroside, 3-glucoside and 3-rutinoside, and as peonidin 3-glucoside and 3-rutinoside, respectively. The composition ratio of the cyanidin 3-glucoside (major pigment) in WP was lower than that of the corresponding cyanidin 3-glucoside of RP.

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