Conductivity of sake, commercial products and during brewing, was measured for the purpose of application of a conductivity meter to evaluating sake brewing process. (1) Temperature characteristics of conductivity of commercial sake was examined, and the temperature coefficient α, of conductivity was derived as a function of temperature. The regression equation computed was:
where symbol designations were:
And it was also able to apply to sake mash. (2) The effect of chemical components on conductivity was examined with model solutions. Significant effect was observed of added organic acids in 15% ethanol solution, and added amino acids in a sake sample. (3) The interactive effect of components in sake mash on conductivity was examined. As the result of multiple regression analysis, the most changes in conductivity was dependent on the increase in amino acidity in sake mash. The single regression equation computed was:
where symbol designations were:
This relationship was applicable to several types of sake mash. These results obtained here suggest that the application of a conductivity meter to evaluation of sake brewing process is feasible.

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Measurements and analysis of physical properties correlated to mouthfeel for several gels were investigated by using a continuous minute deformation method of the multi-biting test developed by our laboratory. Differences in physical properties correlated to mouthfeel for 1% agar gel, 5% gelatin gel, 4% Ina agar gel, 5% ultra 30 agar gel and gellan gum KB gel were clearly indicated by this method. By using continuous minute increasing deformation simulated to mastication, apparent hardness of each gel could be analysed by dividing into gel hardness and recovery strength due to elasticity by our method. Analysis of the changes for the ratio of work load of plunger in 1st bite vs. 2nd bite in modified twice bite method due to increasing deformation, also effective to elucidate the breaking properties of each gels. Elastic modules and viscosities measured by stress relaxation and analysed with mechanical model corresponding to a general combination of Maxwell model of each gels were not useful to characterize the physical properties correlated to mouthfeel of these gels.

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For the purpose of inactivation of pectinesterase (PE), Valencia orange juice was treated by micro-bubble supercritical carbon dioxide (SC CO₂) method. Three cylindrical micro-pore filters (2, 7 and 10μm pore size) were tested for efficiency of the treatment. Among them, the filter (10μm pore size) could yield the highest CO₂ concentration (0.92mol/l at starting time) in a sample solution, so that the efficiency of inactivation was greatly improved. After the treatment at 25MPa and 35°C for 30min, residual activity of PE decreased from 43.1% (without the filter) to 6.1% (with the filter). The following results were obtained with the filter. At each treatment temperature of 35, 45 and 55°C, higher pressure and/or prolonged treatment time caused greater decrease of PE activity. Especially, the large inactivation was observed at 35°C. The residual activity-CO₂ density profile showed the abrupt decrease of the activity when the CO₂ density was above 0.79g/cm³

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Multiple physical tests using a compression tester (Tensipresser) were performed to realize many-sided quantification of physical properties of individual cooked rice and to develop an objective method for measuring texture of cooked rice grains. It was considered that compression ratio in low compression tests (small deformation) was appropriate to be set for minimum 25% for detecting narrow difference between varieties in both hardness and stickiness on the outer layer of cooked rice grains. In compression tests, the repeatability in high compression test (90% deformation) was better than that in low compression tests (15%, 25% and 35% deformation). And also the repeatability of stickiness (-H₁) was worse than that of hardness (H₁) in each compression test. It was possible to evaluate physical properties of the outer layer and the overall of cooked rice grain and to distinguish subtle difference in varieties by combined evaluation with two compression tests (25%-low and 90%-high). With respect to continuous progressive compression test (CPC test) based on the new principle for detecting compression force and reverse force continuously when cooked rice grain was compressed progressively at the continuous amplitude of vibration, elastic limit length (ELL) showed low coefficient of variance comparatively and was able to display the feature of each variety. We concluded that hardness and ratio of elastic limit length (RELL) by two tests (25%-low compression test and CPC test), introduced newly, can differentiate the feature of each variety well and the combination of these tests is appropriate as an objective method of cooked rice texture.

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The purpose of this study was to investigate whether soybean as raw material for processed foods could be affected in texture by an exposure to high-humidity air containing ultrafine water particles. Soybean was kept to stand in a new type refrigerator named Shinki store-box, which could be supplied the high-humidity air containing water microclusters. This high-humidity air was generated by the separation in a cyclone of microscopic water drops which was formed by cracking and splitting water in air flow. The Shinki store-box humidified soybean much faster than other conventional ones of high-humidity being provided by evaporation-condensation system. And a scanning electron microscopic observation revealed a morphological change of the tissue of soybean. Storing in the Shinki stimulated soaked soybean in sucking water even at a lower temperature. Boiled soybean after an exposure to the high-humidity air was found to get softer than convention-ally treated soybean in terms of rheological factors. An application of the high humidity air to soybean processing was discussed.

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Goishi-cha is a local tea produced in Kochi prefecture in Japan. The drinking tea prepared from it contains abundant lactic acid. Two processes of natural fermentation by molds and lactic acid bacteria participate on the procedure of Goishi-cha production. Aspergillus fumigatus, Aspergillus niger, Penicillium sp. and Scopulariopsis brevicaulis were identified from molded tea leaves. Lactic acid bacteria isolated from fermenting broth containing tea leaves tightly packed in a tub was only Lactobacillus plantarum. A. fumigatus, one of the molds appeared on molded tea leaves, possessed the activity to disintegrate a filter paper. Then it was considered that tea leaves are wounded by A. fumigatus, and nutrients leaked from their cells are utilized by lactic acid bacteria in the following fermentation.

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Most of the wheat cultivars grown in Japan was bred for white noodle (Udon) making. Among important objectives of wheat breeding are improved milling quality and eating quality for white noodle, and therefore breeders need objective tests for quality evaluation that is applicable in the early stage of breeding program. Particle size measurement with a laser diffraction particle size analyzer and a modified swelling power test have been used to evaluate the grain hardness and flour swelling character of five imported wheat classes, 133 Japanese cultivars and 63 breeding lines and 34 Australian cultivars. Imported hard wheat classes, i.e. No. 1 Canada Western Red Spring wheat (1CW), U.S. Dark Northern Spring wheat (DNS) and U.S. Hard Red Winter wheat (HRW), yielded wholemeal with coarse particle size, while soft wheat, U.S. Western White wheat (WW), yielded wholemeal with fine particle size. The particle size of wholemeal from Australian Standard White wheat (ASW) was intermediate. Swelling power value of ASW was extremely high, WW intermediate and hard wheat classes comparatively low. ASW, which is known for good white noodle quality, was characterized with moderate hardness and higher swelling power. Among Japanese cultivars and breeding lines examined, cv. Chihokukomugi, Kanto 107 and Kanto 79 had higher swelling power values corresponding to ASW, but their mean particle sizes were smaller than ASW. Although some Japanese cultivars had hard endosperm texture, their swelling power values were low compared with ASW. Among Australian cultivars, the swelling power values of hard cvs. Sunelg and Takari were as high as that of soft cv. Rosella.

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We have proposed a new cutting method named "Cryo-cutting" for frozen foodstuffs by applying a bending force instead of conventional cutting methods with band saw. This paper investigated the effect of muscle fiber angle (θ_f) to cut surface angle (θ_s) of frozen tuna muscular tissue at -70, -100 and -130°C for the purpose of evaluating the applicability of the cryo-cutting method to frozen fishes. The results were as follows: (1) There were two typical cutting patterns ("across the muscle fiber" and "along the muscle fiber") in frozen fish. When muscle fiber angle was 0°≤θ_f≤30°, the frozenmuscular tissue test pieces were cut "across the muscle fiber" and almost all theirθ_s were 90°, and in particular at -70°C, all the test pieces were cut at a right angle (θ_s=90°). When muscle fiber angle was 40°≤θ_f≤90°, the test pieces were cut "along the muscle fiber" and all the test pieces were not cut at a right angle (θ_s≠90°) except the case of θ_f=90° When muscle fiber angle was 30°≤θ_f≤40°, the test pieces were cut in either of these two cutting patterns. (2) We predicted that whole frozen tuna body that made of muscle fiber and connective tissue, was possible to cut frozen tuna body (round shape) in a loin shape by bending them atθ _f=90° and in a chunk shape by bending them at -70°C.

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The properties of tofu-gel made from soymilk produced on a continuous system (CS-tofu) were compared with those of tofu-gel made from soymilk produced on a traditional batch system (BS-tofu). To both types of soymilk, glucono-δ-lactone (GDL) was added as a coagulating agent. Each type of soymilk was then subjected to coagulation under normal heating conditions (at 90°C), and to coagulation in a retort (at 120°C under 2.0kg/cmcm²). A scanning electron microscope revealed that under normal heating conditions BS-tofu and CS-tofu had well defined network structures. The retort-coagulated CS-tofu also had a clearly defined network structure, but breakdown was evident in the network structure of the retort-coagulated BS-tofu. The physical properties of each type of tofu were measured using a Tensipresser. The retort-coagulated BS-tofu displayed overall firmness, but lost its cohesiveness and showed overall shrinkage. However, Cs-tofu (even the retort-coagulated type) showed increased firmness. It retained its cohesiveness and did not shrink significantly. Such differences in tofu gel properties were affected by the standing time between soybean grinding and heating process.

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The tuber of Arisaema has been eaten for a long time as a food of an off-crop season in Hachijou-island, Okinawa and Hokkaido. In Hachijou-island the tuber is taken after processing to dango called Hengo-dango that has very strong stickiness. In this paper, the properties of starch which is a main component of Arisaema tuber were investigated. The onset temperature of gelatinization of Arisaema starch was 61.7°C, which was a little lower than that of potato starch. Maximum viscosity value in Rapid Viscogram was 346 SN, which was higher than that of corn, and lower than potato starch. Amylose content was 35.4%, which was about two times higher than that of taro starch. In X-ray diffractometry, Arisaema starch showed B-pattern, in spite of the starch of taro which belongs to the same family, and the reported pattern of which was A-pattern. Scanning electron microscopy showed that average particle size of starch granules of Arisaema was 10.5μm with smooth surface. This configurational properties were different considerably from those of taro starch whose particle size was about 1.1μm with rough surface.

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The effects of phloxine (Food red No. 104) and β-carotene on oxidative deterioration of oil were investigated by the Rancimat method (Metrohm Co. Ltd E 679, Herisan Switzerland). Oils (olive, soybean and whale oils) with or without phloxine and β-carotene were tested at 120°C, and air current is passed through the oil to be tested. The Rancimat method is based on the conductometric determination of volatile degradation products of oil and automatic plotting of the conductivity against time. The evaluation is performed graphically after completion of the experiment. Induction time (rancid point) of oil was shortened by the addition of phloxine, indicating that the oxidative deterioration of oil was promoted by phloxine. On the other hand, β-carotene showed preventive effects on the oxidative deterioration of oil. The results shown here of phloxine and β-carotene on the oxidative deterioration of oil were similar to those obtained by the oven test.

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Okara-tempe (OT) is fermented okara (OC) by Rhizopus oligosporus (a fungus to make Tempe). In this paper, the effects of fermentation on the digestibility of OC protein were studied by using rats. By comparing OT with OC in respect of free amino acid content and the distribution of molecular weight of proteins, OT contained more free amino acids and lower molecular weight proteins than OC. The results suggest that some parts of OT proteins are decomposed into low molecular weight substances by the fermentation of OC. On optical micrograph of the digestive residue from rats fed on OT or OC diets which contained OT or OC proteins as the only source, the proteins in the cecum residue of OT diet were not detected appreciably, but those of OC diet were clearly observed. In the feces residue of OT or OC diets, any protein was not observed. It is presumed that both proteins of OT and OC will be completely digested, and OT protein will be digested easier than OC protein in rats.

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Volatile components contained in raw and pasteurized Japanese soy sauce of the koikuchi type (koikuchi shoyu) were compared among the products from nine different plants using two different koji molds, Aspergillus sojae No. 9 (A. sojae No. 9) and Aspergillus oryzae S-03 (A. oryzae S-03). Identific-ation of the volatile compounds in koikuchi shoyu and the quantitative comparison were carried out by GC, GC-MS analyses and the analysis of variance of the GC peak areas. Sixty-five compounds were identified or estimated as koikuchi shoyu volatile components, in which five compounds were newly confirmed or tentatively identified in koikuchi shoyu. The quantity of A. sojae No. 9 koikuchi shoyu volatiles was larger than that of A. oryzae S-03 koikuchi shoyu, and it increased when the koikuchi shoyu was heated. 2-Methyl-1-butanol, 3-methyl-1-butanol, ethyl lactate, acetic acid, and 2-phenylethanol, etc., besides ethanol, had large peak areas on the gas chromatograms of the koikuchi shoyu. Ethyl lactate, acetic acid, pyrazines, phenylacetaldehyde, phenol, and maltol, etc., were larger in A. sojae No. 9 koikuchi shoyu than those in A. oryzae S-03 koikuchi shoyu. On the other hand, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-phenylethanol, 2-methylbutanoic acid, 3-methylbutanoic acid, 3-methylthio-1-propanol, 2-ethyl-4-hydroxy-5-methyl-3 (2H)-furanone, 4-ethylguaiacol, and 4-ethylphenol, etc., were found in abundance in A. oryzae S-03 koikuchi shoyu.

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