The industrial procedure for the preparation of dietary fiber materials from corn pericarp by wet milling process was developed. The hypocholesterolemic effects of refined corn bran (RCB) and its isolated hemicellulose (soluble corn fiber, SCF prepared by these procedure) were examined in rats fed a hypercholesterolemic diet containing 1% cholesterol and 0.25% sodium cholate. (1) RCB, CB (corn bran), WB (wheat bran) were supplemented to a diet at a level of 5% total dietary fiber. The diets were given to rats for 9 days. RCB was effective in preventing elevation of serum cholesterol levels compared with WB. RCB also tended to have strengthened hypocholesterolemic activity compared with CB. (2) SCF and CBH (corn bran hemicellulose prep.) were supplemented to a diet at a level of 2%, respectively. These substances had a significant effect on preventing the elevation of serum choresterol and also on depressing the increase in liver cholesterol content of rats compared with CP (cellulose powder). RCB and SCF, natural fiber supplement from corn can play a role in achieving health benefits.

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The check of the milk curd formation is an essential item in a process of yoghurt-or cheese-making. The termination of yoghurt fermentation and the cutting time of cheese curd in a bat are decided with conditions of milk curd, and such decisions are mainly performed by men of experience. In order to monitor the conditions of milk curd formation continuously and to decide the cutting time of cheese automatically, an apparatus was developed, As the milk curds formed are easily broken by mechanical force, the method without mechanical force has been required for continuous monitoring. For the purpose of this requirement, the Peltier unit attached with thermocouple sensors just close to the both surfaces, was investigated. The Peltier unit can generate heat at one side of surface and absorb heat at another side of surface by the application of direct current. When the apparatus is soaked in a sample and the both surfaces are maintained at different temperature with the sample, the heat transference from the surface of the Peltier unit to the thermocouple sensors depends on the condition of the sample between the surface and the thermocouple sensor. The low viscosity of the sample causes a high tendency of convension current and results few influence upon the temperature of thermocouple sensor, on the other hand, the high viscosity makes convension current difficult and in consequence, the heat flow from the surface to the thermocouple sensor increase. Accordingly, the viscosity or the flowing tendency of sample was supposed to be known by mean of the temperature difference between the thermocouple sensors of both side of Peltier unit. When the apparatus was employed for the yoghurt and cheese processing test, it could precisely detect the increase of viscosity and the begining of coagulation. Furthemore, the apparatus was hardly influenced by practical temperature variation.

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[KaU-09], one clone of Dioscorea alata L., was grown in Kagoshima district and freshly harvested tubers were stored at different temperatures to examine the effect of storage condition on the quality of yam. Judging from external appearance of tuber during the storage at 15°C, 13°C and 10°C, it was suggested that appropriate storage temperature was 15°C, and at this temperature the tubers were stored for 6 months in healthy condition. The tubers stored at 10°C became soft at all parts and their cut section showed grayish color which was different from the creamy white color of the healthy tubers. On storage at 13°C injury was observed as the appearance of spots on the surface. In the course of 5 month-storage at 15°C, the content of viscous polysaccharides in the tuber decreased linearly (to 70% of the initial content) followed by the change in rheological properties (apparent viscosity, thread forming capacity) of the homoginate of yam, called "Tororo" in Japanese. On storage at 10°C, the tubers lost the viscous property, and this was assumed to be due to change in the property of viscous polysaccharide molecules. Amylase activity of the tuber stored at 15°C reached the maximum (3.5 times of the initial activity) after 8 month-storage.

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Bacterial spoilage of film-packaged kamaboko during cold storage was investigated. The film-packaged kamaboko made by 15 makers were stored at 10°C for 30 days. The patterns of spoilage were divided into 3 types; (1) softening of tissue, (2) development of slime and (3) mold. The causative bacteria isolated from the soft spoiled kamaboko was identified as Pseudomonas sp.. The causative bacteria isolated from the slime-type spoiled kamaboko were identified as Leuconostoc sp., Micrococcus sp., Pseudomonas sp., Enterobacteriaceae, Staphylococcus sp., Corynebacterium sp., Vibrio sp. and Yeast. The fluorescent pigments of Pseudomonas was detected on the basal medium divised for the fluorescent Pseudomonas after incubation at 30°C for 2 days. The recipe of the basal medium is shown as monosodium glutamate 5.00g, K₂HPO₄ 0.12g, NaCl 1.00g, MgSO₄·7H₂O 0.70g, mannitol 10.0g, agar 15.0g and distilled water 1.0l. Using the basal medium the fluorescent Pseudomonas was detected in every process of manufacture except the inside of heating apparatus. When the Pseudomonas isolated from the each process of manufacture and kamaboko on the market were inoculated onto kamaboko, the softening and production of fluorescent pigments were observed on its surface, but some Pseudomonas did not cause spoilage. P. fluorescens biovar V, Micrococcus sp. and Leuconostoc sp. were penetrated to "Folding packaged kamaboko" and "Retainer shaped kamaboko". From the results contaminated mechanism of causative bacteria was conjectured as follows. (1) When the kamaboko arrived at the process line after being heated, typical causative bacteria like Pfluorescens biovar V attaches to the outside of its wrapping. (2) The causative bacteria penetrate the folding area of the wrapping, during the storage at low temperature. (3) The causative bacteria arrives at the surface of kamaboko by the motility on flagella, "Brownian movement" of bacteria and a capillary phenomenon of contaminant. (4) As the arriving bacteria grows, the spoilage occures at last.

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Softening of 'Sordum' plum fruits is suppressed when stored at 30°C. Changes in the composition of pectic substances, pectinesterase (PE) activity and polygalacturonase (PG) activity were investigated to clarify the suppression of softening of the fruits during storage at 30°C. The fruits were stored at 30°C, 20°C and 3°C. (1) The fruits softened remarkably from the beginning of storage at 20°C, but the fruits stored at 30°C softened slower than those at 20°C. The fruits hardly softened during storage at 3°C. (2) A decrease in hydrochloric acid-soluble pectin and an increase in water-soluble pectin were observed at 20°C. But, each pectic substance hardly changed during storage at 3°C and 30°C. (3) The optimum temperatures of PE and PG activities were around 57°C and 40°C, respectively. (4) PE and PG activities hardly changed during storage at 3°C. At 20°C, however, PE activity increased rapidly from the beginning of storage and PG activity increased rapidly especially after storage at 7 days. Although the activities of both enzymes increased gradually at 30°C, they were suppressed to low level compared with those at 20°C. As a result, it was suggested that the repression of PE and PG activities caused suppression of the softening of 'Sordum' plum fruits when stored at 30°C.

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A biosensor system for continuous determination of fish freshness using one of the the freshness indices [Ki={(HxR+Hx)/(IMP+HxR+Hx)}×100] of fish, where the IMP, HxR and Hx are inosine monophosphate, inosine and hypoxanthine contents, respectively, was developed. The system consisted of two immobilized enzyme reactor electrodes, an A/D converter, a microcomputer and a peristaltic pump. Nucleoside phosphorylase (NP) and xanthine oxidase (XOD) were simultaneously immobilized onto alkylamine glass beads which were then packed into a column (φ3×50mm), and the enzyme reactor electrode for HxR and Hx was prepared combining this co-immobilized enzymes column and an oxygen probe. Similarly, 5'-Nucleotidase was immobilized together with NP and XOD, and the electrode for IMP, HxR Hx was prepared combining this co-immobilized enzymes column and an oxygen probe. One assay could be completed within 5min. The relative errors was 4.6% for determination of fish freshness (n=30). The immobilized enzymes were sufficiently stable for at least one month at 4°C. The results for fish meats (skipjack, horse mackerel, plaice, Japanese red bream, yellowfin tuna) correlated satisfactorily well with those obtained by HPLC method (γ=0.996).

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Seven kinds of spices were irradiated with gamma-rays at the dose of 5 to 80kGy. Studies of radiation effect on lipids in each spice were carried out by measuring peroxide value (POV), iodine value (IV), acid value (AV) and analysis of gas-chromatography (GC). POV in each spice was gradually increased with increasing absorbed doses. The increase of POV in nutmeg was higher than those of other spices, and it was suggested that those increase of POV values were related to lipid contents in spices. A little increase of IV and AV were also observed as same amount of POV by the irradiation up to 80kGy. From the GC analysis of lipids in each spice, components were not changed even irradiated up to 50kGy of gamma-rays. Radiation effect on components of essential oils in each spice were also analyzed by headspace-GC (HS-GC), and any degradation of components were not observed up to 50kGy of irradiation even analyzed by GC after separation to hydrocarbon and oxygen compounds. On the contrary, essential oils of cloves sterilized by heat treatment were apparently decreased as compared with irradiated and non-irradiated cloves.

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Applicability of a newly developed ultrasonic cutter to sample preparation for rheological measurements of foods and food materials has been evaluated by creep measurement and surface observations with optical and scanning electron microscopes and campared with a cooking knife.
The elasticity (E₀, E₁, E₂) and the viscosity (η₁, η₂, η_N) of castella and processed cheese samples prepared with the ultrasonic cutter were significantly larger than those with the cooking knife. No significant difference was obtained in these reological values for kamaboko samples prepared with ultrasonic cutter and cooking knife.
The surfaces of both castella and cucumber sliced by the ultrasonic cutter were more smooth than those sliced by cooking knife. There was no significant difference in the surfaces of both kamaboko and cheese sliced by ultrasonic cutter and the cooking knife.

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A comparative study for determination of dietary fiber (DF) in soybean was carried out using the following methods; an enzymatic-gravimetric method for total dietary fiber (TDF) (PROSKY method), another enzymatic-gravimetric method for insoluble and soluble dietary fiber (IDF and SDF) (modified PROSKY method), and a method for fractionation into noncellulose polysaccharide, cellulose and lignin followed by analysis of their constituents (SOUTHGATE method). There was no substantial difference in TDF content among three methods. However, in PROSKY and modified PROSKY methods a part of SDF was lost during the filtlation using fritted crucibles of porosity No. 2 (40-60μm). The suitable filter was found to be porosity NO. 3.5 (16-40μm). In SOUTHGATE method, working curve using galactose as standard was superior to that using glucose for galactose content more than glucose in soybean. Roasted soybean contained less IDF and more SDF than raw soybean.

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In order to get additional information on antimicrobial action of sucrose monoalkylates, which are approved as food additives, we studied the effects of the esters on growth of heat-resistant Bacillus stearothermophilus spores, by comparison with those of a variety of surfactants differing in the chemical structure. Sucrose monoalkylates and several other surfactants inhibited the growth from spores, by preventing spore germination. The inhibitory effectiveness of surfactants is closely related to hydrophobicity of surfactants rather than their intrinsic chemical characteristics. Surfactants acted on spores in a bacteriostatic manner.

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Heat-induced ovalbumin gels prepared under given conditions were melted with a second heating to below 90°C. The sample melted was gelled again on cooling. This gel-sol transition, which was detected both by eye and by the change in the dynamic viscoelastic parameters G' and G", was reversible. Differential scanning calorimetry showed that the endothermic heat flow that accompanied the gel-sol transition was much lower than that accompanied the denaturation of ovalbumin. With the repetition of the gel-sol transition, intermolecular disulfide bridges were formed, detected by sodium dodecyl sulfate-polyacrylamide electrophoresis done without a reducing agent.

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Polygalacturonase (EC 3.2.1.15) (PGase) and invertase (EC 3.2.1.26) activities were compared with the untreated and the treated papaya thermally injured by vapor-heat treatment. PGase activity was higher in the normal fruits, and invertase activity was only slightly higher in the thermally injured fruits. The appearance of the thermally injured fruits might be caused by the effects of PGase. The rate of ethylene generation was studied by soaking the papaya in a methionine solution of ethylene precursor or an Ethrel (2-chloroethyl phosphonic acid) solution of an ethylene generating chemical. The results showed that the ethylene production rate was relatively higher in fruit treated with an Ethrel solution for both untreated and thermally injured fruits, and a quality improvement of the thermally injured fruit was suggested.

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