Mouthfeel of cooked buckwheat noodles ("Soba" in Japanese) and their textural changes with standing time were studied. Analysis of the fracture behaviour of foods by using the textural instrument is very important subject in investigation of the mouthfeel of foods. Textural measurement of mouthfeel of cooked Soba was conducted with biting test using the Tensipresser. New textural parameter of fracturability index was introduced by the author, which could express fracture properties of Soba and its changes with standing time numerically as well as fairly quantively. Fracturability index is a ratio of biting distance when the first significant fracture appears to total biting distance of a plunger in a Tensipresser biting profile curve of food using a plate type plunger. Fracturability index had a good reproducibility in the textural measurement of cooked noodles compared to the usual parameter of fracturability. Optimum fracturability of cooked Soba which had good mounthfeel in the sensory test could be expressed by figures as the fracturability index of about 0.74. In the textural changes of cooked Soba with standing time, steep increase of adhesiveness was observed, which also related to the textural (mouthfeel) changes of cooked Soba with standing time ("nobiru" in Japanese).

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On the blending of fresh coffee and stale one, an additional effect was observed regarding the concentration of each component and fresh coffee could not improve the aroma of stale coffee. The mutual interaction of volatile components was observed in the case of blending two varieties of fresh coffees, but there was no additional effect. The addition of ethanol, milk and sucrose reduced the total concentration of volatile components in the headspace. In the addition of ethanol and milk, peaks 2(unknown), 4(n-hexane), 7(propionaldehyde) and 9(2-methylfuran) decreased but the mechanisms of the action were different. In the case of sucrose, all volatile components decreased with different decreasing percentages. Incidentally, when 1.0ml of ethanol was added to 100ml of coffee brew, the total amount of aroma decreased by 10.0% and 5.0ml of milk, 3.2%; 10.0g of sucrose, 18.4%, respectively.

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Textural properties of SCP (Baker's yeast protein) fibers with or without addition of carrageenan were studied. As fibers are usually further processed to make fabricated products, egg white was used as a binder to formulate two structural phases. The measurement of the compression or penetration was conducted by using the Instron type universal testing machine and the comparison of them was also made with some commercial foods to evaluate Texture Profile Analysis (TPA). Carrageenan-SCP model food showed less than 70-80% of the compression strength compared with SCP model food. These model food required higher force than egg white control and big difference was observed during the second and third bite. These results suggest that incorporation of spun fiber in egg white increases the elastic properties of the test piece, which seems to be responsible for the network structure of fiber and binder. Moreover, penetrating strength of SCP or carrageenan-SCP model food at the first bite were higher than that of fish meat sausage and mixed sausage. TPA values of SCP model food are equivalent or superior to some of these commercial foods suggesting that mechanical properties of SCP fiber-egg white binder has similar characteristics to them. Addition of oil, wheat gluten and/or soy flour may improve model foods.

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A stability of wheat germ oil against thermal oxidation and autoxidation was compared with soybean, cottonseed and corn oils. The nutritionally deleterious dimer glycerides produced in heated oils were also determined. Furthermore, the composition of unsaponifiable matter in wheat germ oil and a presence of antioxidative compounds except tocopherols were investigated. Thermally oxidized oils were prepared by heating fresh oils at 180±2°C for 8 hours a day for 6 days. Several chemical characteristics of the thermally oxidized oils indicated that a stability of wheat germ oil against thermal oxidation was superior to soybean oil but not good as cottonseed and corn oils. The stabilities of fresh and thermally oxidized oils against autoxidation in oven test were almost similar to those of thermal oxidation. There was no significant difference of the contents of dimer glycerides among the thermally oxidized oils and also the quantities produced in those oils seemed to be negligible for deleterious effect on nutrition. Major component in unsaponifiables of wheat germ oil was sterols and tocopherols were present in minor quantity. However, the contents of total, and α-and β-tocopherols in wheat germ oil were the highest when compared with other vegetable oils. Presence of antioxidative component other than tocopherols in unsaponifiables of wheat germ oil was not recognized. Wheat germ oil is not suitable for frying oil because of its less thermal oxidative stability. Wheat germ oil contains high quantity of linoleic acid, and physiologically active α-and β-tocopherols, so it is preferable to ingest this oil as fresh.

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Cellulase (1, 4-β-D-glucan 4)-glucanohydrolase, EC 3.2.1.4 from Aspergillus niger was immobilized on cyanogen bromide activated agarose beads (Sepharose CL-6B). Over 90% of protein was immobilized and 24% of cellulase activity was retained. Some properties of immobilized cellulase were investigated and compared with those of native cellulase. (1) pH profile of immobilized cellulase activity was not altered, as compared with native cellulase, but the immobilized cellulase was stable at pH 2-8. (2) The immobilized cellulase showed good thermal-stability, 90% of carboxymethyl cellulase (CMC-ase) activity remained at pH 4, 60°C, and 60% was maintatined at pH 2, 50°C when it was incubated for 1hr. (3) The residual activity was about 50% after 8 days storage at pH 2, 25°C. (4) Enzyme did not leak from immobilized cellulase, and 80% of the initial activity was maintained after 15 times repetition of the reaction. (5) Paper chromatography of the hydrolysate of CMC with immobilized cellulase showed that the reaction product was glucose as is the case with native cellulase preparation.

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The thermal processing for soymilk, which was capable to inactivate spore-forming microbes and to ensure the favorable consistency, was tested in order to facilitate the manufacture of Tofu products with satisfactory keeping quality. HGU method, an advanced thermal process for soymilk by means of UHT process with preceding germination subsequent to heat activation, was developed in the present study. The results obtained were summarized as follows; (1) Stimulation of germination of externally-added Bacillus subtilis ATCC 6633, to a rate of 74%, was achieved by heat activation of soymilk at 80°C for 10min while the rate of germination without the heat activation was 63%. Subsequent germination process at 37°C for 30min led to a higher germination rate up to 86%. (2) In order to inactivate spore-forming microbes in soymilk which were migrated from the soybean or externally contaminated during soymilk production, the heat activation and the germination processes were prerequisite and the practice of these two processes in sequence was observed to be more effective for the production of Tofu having satisfactory keeping quality. (3) The period for keeping quality was significantly prolonged by holding the soymilk, prepared by subjecting to heat treatment at 100°C for 4min, at 5 to 15°C for 17h prior to heat activation process as compared with the case of immediate heat activation of the soymilk omitting an intermediary cooling process described above. (4) The effect of the practice of the sequential heat activation and the germination processes upon the germination of spore-forming microbes, was more convincing when the subsequent UHT process was conducted at 125°C as compared with the case of UHT process at 130°C. (5) The soymilk, prepared by the HGU-method, ensured a more favorable flavor persistence in resulted Tofu than in those which were prepared by the traditional method. Tofu prepared by the former procedure was equivalent to those prepared by the latter one with respect to physicochemical properties such as color, and consistency, in addition to the improved keeping quality.

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Mouthfeel of Kamaboko was analysed by biting test and the multi-point mensuration method using the Tensipresser. Three types of plungers (stick, knife and plate types) were used. Analysis of the Tensipresser bite profile curves was useful for detecting differences of the mouthfeels amoung commercial Kamabokos especially by using a plate type plunger. Multi-point mensuration was also essential for analysing the mouthfeel of Kamaboko. HY (hardness at apparent yield point), HR (hardness at rupture point), AI (mechanical work load of the plunger in the first bite), αA1(0.20-0.95) (slope of AI vs. biting ratio from 0.20 to 0.95), fracturability index and cohesiveness (measured at 50% bite) were the principal parameters to estimate the mouthfeel of Kamaboko numerically.

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Chlorogenic acid was extracted from pulp of matured apple with methanol and fractionated by passing through a column of insoluble polyvinylpyrrolidone. The chlorogenic acid analogues in the effluent were determined by measuring the absorbance at 324 nm. The procedure of passing through the column removed most of contaminants from the extracted solution. The effluent gave a spectrum in the ultraviolet region closely similar to authentic chlorogenic acid as well as a clear spot identical with chlorogenic acid on thin-layer chromatogram with insignificant tailing. Chlorogenic acid content in apple pulp increased slightly during storage at 0°C for 2-3 months after harvest.

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Antioxidative activities of horse radish and mustard powder and synergistic effects of these powders with tocopherol were investigated. (1) Mustard powder had stronger antioxidative activity than that of horse radish powder. (2) By deactivating of myrosinase by boiling with water and/or 70% methylalcohol, antioxidative activities of horse radish and mustard powder were increased. (3) Sinigrin showed antioxidative activity but its effect was low. (4) Antioxidative activity of fat extracted from mustard powder was not observed but that of mustard powder was multiplied about 2 times by defatting. (5) Antioxidative activity of isolated protein from mustard powder was weaker than that of original one. (6) Antioxidative activity of mustard powder (heated) was 2 times stronger than that of tocopherol preparations. (7) Synergistic effect of mustard powder with tocopherol preparation was reconized but that with miso was not observed. (8) In application test of addition of mustard powder to biscuit, oxidative stability of biscuit was highly improved.

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An applicability of near infrared reflectance (NIR) technique was examined to determine a capsaicin content in red pepper. Spectra of the 13 red pepper samples were measured in the region of 1.1 to 2.5μm by a computer-controlled spectrophotometric instrument and the major absorption, bands were investigated with regard to the bands of its related substances such as capsaicin, sucrose fructose and glucose. The stepwise multiple linear regression analysis was made to select the five wavelengths in the order of 2.422, 2.358, 1.974, 1.622 and 1.820μm so that chemically analyzed capsaicin contents could be correlated to the derivative values of absorption at the wavelengths. The correlation coefficient was 0.993 and the standard error of estimation was ±0.0036%.

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An automatic data processing for texture profile analysis (TPA) by using a personal computeronlined rheometrical system has been developed, and the performance and applicability of the system were evaluated by comparing the result of data processing by computer with that of manual treatment. The data-processing program for calculating of textural parameters was developed by using BASIC language. The results of the data processing for TPA were in good agreement with those of manual treatment. Correlation coefficients between manually measured TPA parameters and compute-assisted data processing using gelatin gels (3%), agar gels (1%) and low methoxyl pectin (LMP) gels (2%) were generally higher than r=0.99. The data-sampling times from the rheometer into the memory of the computer was 35 ms per 1 point of data. The data processing time for textural parameters was 2min per 1 data file (2400 points of data).

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