The effect of ozone exposure (concentration: 0, 0.03, 0.1 and 0.3ppm) during different cultivation processes of Winter Mushroom (Flammulina velutipes) was investigated on the weight, chemical composition (water, protein, lipid, carbohydrate and ash as major constituents; Ca, Fe, Na, K and Zn as minerals; thiamin, riboflavin and ascorbic acid as vitamins), and the fatty acid composition on dry matter basis of fruit body i.e., pileus, stipes and the whole. A significant increase was observed in weight when fruit body primodia in early stage were exposed to ozone, while, a significant decrease was observed in it when fruit bodies in early stage of development were exposed to ozone. In the former condition, an increase was observed in carbohydrate, Ca, Na, K and thiamin and palmitic acid contents in pileus, in Ca and oleic acid contents in stipe, and in Ca content in the whole. On the other hand, a decrease was observed in Fe, Zn and oleic acid contents in pileus, in carbohydrate, Fe, Na and thiamin contents in stipe, and in carbohydrate, Fe, Zn, thiamin and oleic acid contents in the whole. As to the latter case, an increase was observed in carbohydrate and ascorbic acid contents in pileus, in ascorbic acid contents in stipe, and ascorbic acid contents in the whole. On the other hand, a decrease was observed in ash, Ca, Na and K contents in pileus, in lipid, Ca, Fe, Na, K and riboflavin contents in stipe, and in lipid, ash, Ca, Na, K and riboflavin contents in the whole.

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Membrane components and cell form of A. polyoxogenes (vinegar producing strain) under high acidic conditions were studied. A. polyoxogenes was inoculated in the medium containing 6% of acetic acid, and the culture was continued until the acetic acid concentration in the medium reached to 8, 12 and 19%. Composition of phospholipid component in the microbe membrane varied with an increase in the acetic acid concentration in the medium. The ratio of phosphatidylcholine increased and that of phosphatidylglycerol decreased as the acetic acid concentration increased. The ratio of phosphatidylethanolamine was little affected. Cardio-lipin was not detected during the fermentation period. Ratio of unsaturated fatty acid in the total lipid was very high, and 86% of the total lipid was cis-vaccenate and its ratio was almost identical through the fermentation. Proteins of A. polyoxogenes cell collected from the broth at several fermentation stages were analyzed by electrophoresis. Some differences were observed among proteins from soluble fractions but not among proteins from membrane fractions containing the enzymes of acetic acid fermentation. SEM of cells of A. polyoxogenes harvested at each acidity showed that the cell obtained at 8 and 12% acetic acid concentration looked much shrinking and the cell obtained at 19% acetic acid concentration looked a normal form. These observations suggest that cell wall also changed with acetic acid concentration. In conclusion, membrane component ratio and cell wall structure of A. polyoxogenes changed according to change of acetic acid concentration in the broth.

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An efficient method to remove astringency from purple cacao beans (insufficiently-fermented beans) was developed. Purple beans contained much of polyphenolic substances than brown beans (well-fermented beans) and showed strong astringency. We have screened enzyme preparations being able to decrease astringency of purple bean water extracts. Polyphenol oxidase (PPO) from Coriolus versicolor was the most effective among the examined enzymes and then it was found that polyphenolic substances in purple bean water extracts were oxidized and insolubilized by the enzymatic reaction. Autoclaved purple beans were soaked in the PPO solution and incubated at 45°C for 3h. The polyphenolic contents of purple beans were decreased to the level of those of brown beans by the enzymatic treatment.

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On the soy protein isolate heated prior to freeze-drying, changes to gel from protein paste during cold storage were already reported by the author. In this paper, the effects of various salts, oxidizing agents, reducing agents and protein denaturants on gel formation of soy protein isolate during cold storage were investigated. In the effect of salts on the gelation, cations prevented gel formation during cold storage, in order of Li⁺<Na⁺<K⁺.In the case of anions, the addition of SO₄^2-, F^- and Cl^-decreased strain of cold-gel than that of Br^-, NO₃^- and ClO₄^- It was shown that the action of anion on strain of cold-gel was in accordance with the Hofmeister order. On the oxidizing agents, potassium bromate and potassium ferricyanide decreased jelly strength and strain of cold-gel. On the reducing agents, sodium nitrite did not prevent gel formation, on the other hand, sodium hydrogensulfite prevented it greatly. On the protein denaturants, 2-mercaptoethanol, N-ethylmaleimide, ethylene glycol and urea prevented gel formation greatly. However, sodium phosphite, ethylene chlorohydrin and 1, 4-dioxane did not affect on gel formation. Based on the aboved-mentioned results, it was suggested that disulfide bond, hydrogen bond and hydrophobic bond mainly take part in gel formation of cold-gel.

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Color changes of liquid crystal due to temperature changes were applied to visualize and to measure the temperature distribution in an imitation food heated by microwave. The liquid crystal sheets made from slurry of liquid crystal were used to determine a relationship between the color of Iiquid crystal and the temperature, and to visualize the temperature distribution. The color changed in the order of red, green, and blue as the temperature increased. To clarify the relationship between the color and the temperature, the color levels of red (R), green (G), and blue (B) were measured respectively from a photograph. The temperature distribution could be evaluated quantitatively from the ratios of color levels (R/B) and (G/B).

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Restrictive hydrolysis of porcine globin by citric acid was investigated. The resulting hydrolyzate contained eight kinds of different peptides. After these peptides were separated from one another by tricine-SDS-PAGE system, the amino acid sequence of each peptide was partially determined. From these results, two kinds of peptides were presumed to be α-chain and β-chain of globin. Three in the remaining six kinds of peptides were derived from α-chain and the other peptides from β-chain. Citric acid specificially hydrolyzed the covalent bond between aspartic acid and proline residues of α-chain and β-chain of globin.

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Frozen surimi from walleye pollack was ground with 2.5% NaCl and sardine lipid which contained EPA and DHA, and then texturized under high pressure of 0-500 MPa at about 13°C for 10min. After the pressure-induced gel thus formed was subsequently stored at 5°C, this gel was incubated at 90°C for 20min to prepare pressure-induced heating gel. Breaking strength (BS) and breaking strain (Bs) of these gels with different lipid contents and lipid oxidation were measured as a function of storage time. As a protein concentration in salt-ground meat was high, the tough gel which showed high values of BS and Bs containing a small quantity of sardine lipid was prepared. On the other hand, in case of a low protein concentration in it, the soft gel which showed low values of BS and Bs containing large quantity of sardine lipid was prepared. In spite of a protein concentration, lipid oxidation proceeded slightly under grinding, a high pressure treatment, heating and storage. Fish lipid was little separated from the gels under the above four stages. These results indicated that various textural food materials with EPA and DHA was easily prepared by high pressure treatment of salt-ground meat containing different ontents of protein and lipid.

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Nineteen species (25 items) of spices listed on Standard Tables of Food Composition in Japan were examined in respect of their effects on α-amylase and α-glucosidase. Synthesized substrates, Starch Azure for α-amylase and p-nitrophenyl-α-D-glucoside for α-glucosidase (PNPG), were added to the water extracts from spices containing the enzyme solution. The solubilized blue pigment from Starch Azure was determined by spectrometry and p-nitrophenol liberated from PNPG by HPLC. Allspice, cinnamon and thyme exerted remarkable inhibiting effects on both enzymes regardless of being cooked. In other spices, various modes in terms of inhibition were observed, and some spices activated the enzymes. A possible use of spices in food preparation to improve glycemic index for diabetic patients were suggested.

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Physiological responses and texture changes were investigated on tomato and cucumber fruits held in high (95%), medium (80%) and low (60%) relative humidity at 20°C. High respiration rates and elevated ethylene productions were observed in both the tomato and the cucumber fruits at low RH. Low RH hastened the peel coloring of the tomatoes in terms of the Hunter L^*, a^* and b^* values. Loss in flesh firmness, which was rapid in the fruit held in low RH, was positively correlated to increased water-soluble pectin (WSP), decreased hydrochloric acid-soluble pectin (HP) and decreased hemicellulose in the tomatoes, and to decreased sodium hexametaphosphate-soluble pectin (HMP) in the cucumbers. These results suggested that water deficit stress in low RH was unfavorable in the view of keeping quality of the tomatoes and the cucumbers, because of accelerating their physiological activities and degrading enzyme activities of cell wall polysaccharides.

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A simple and easy method in microdilution wells was designed and established for economical routine assay of activity of thrombolytic enzyme extracted with physiological saline from "natto". The optical density at 655nm (OD₆₅₅) was decreased linearly by the lysis of artificial fibrin in microdilution wells during incubation at 37°C. Based on-ΔOD₆₅₅ calculated by subtracting OD₆₅₅ of microdilution wells before adding the "natto" extract from OD₆₅₅ at individual indicated incubation time, the CV% was found to be within 10% throughout various degrees of dilution of the "natto" extract. Logarithmic values of the degree of dilution of "natto" extract and-ΔOD₆₅₅ showed a linear relation, irrespective of the sample quality, indicating that this is a good method for the determination of thrombolytic activity in "natto" products.

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The effects of temperature and salt concentrations for fermentation of "NISHINZUKE" were investigated and the following results were obtained. Though gram-negative bacteria were predominant among the microorganisms on the early stage, they were killed and decreased by accumulation of lactic acid produced by lactic acid bacteria during storage. The bacteria counts of Lactococci were about 10⁶/g in the first stage, but those of Lactobacilli were about 10³/g. The bacteria counts of both Lactobacilli and Lactococci increased to about 5×10⁸/g at 10°C for 5 day. In the "NISHINZUKE" fermented at 10°C, marked increase in Pichia spp. were found in the later stages of fermentation. The quality of "NISHINZUKE" was stable under at 5°C for 35 days but unstable at 10°C.

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Synthetic paste has been used as a material for the visualization of temperature distribution in a food heated by microwave. In this investigation, dielectric properties of synthetic paste were measured at 2450MHz and 915MHz from 20°C to 75°C. These values were compared with those of water. The dielectric constant of synthetic paste was slightly smaller than that of water. However, the dielectric loss factor of synthetic paste was larger than that of water. As a result, penetration depth of synthetic paste, the distance where the electric power is decreased to 1/e of its surface value, was rather smaller than that of water.

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The yeast Torulaspora pretoriensis YK-1 has both high potential leavening ability and freeze-thaw resistance, but its maltose fermentation rate is much less than Saccharomyces cerevisiae FL 2209 isolated from commercial compressed yeast, resulting in low leavening ability in the dough without addition of sugar. We found that IFO 0022, other strain of T. pretoriensis leavened dough more efficiently than YK-1 without the addition of sugar although the potential leavening ability was lower. Freezethaw resistance of IFO 0022 was high and similar to that of YK-1 as compared with that of FL 2209.

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Tempe was prepared with velvet bean using pure cultures of Rhizopus oligosporus (IFO 8631) and consequent changes in free amino acids content were examined. A ninhydrin positive unknown compound detected as methionine in an amino acid analyzer chromatogram was isolated by ion-exchange and gel-filtration column chromatographies and identified. The compound was determined as 3, 4-dihydroxyphenylalanine (DOPA). Total content of free amino acids of tempe was 0.8g/kg dry beans, corresponded to 17% of that of dry beans. Most free amino acids unchanged in the 1st soaking and boiling, decreased in the 2nd and 3rd soakings, and increased during fermentation. Their content decreased by 7% on dehulling. DOPA which was abundant in velvet bean decreased in the 2nd and 3rd soakings, and 30% DOPA of that of dry beans remained in tempe.

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The purpose of this work was to study the effects of hydrostatic pressure treatment on sterilization, viscosity and browning of grated yam (Dioscorea. cv. Nagaimo) named "Tororo". Most of fungi and gram-negative bacteria in "Tororo" were sterilized by pressure treatment more than 500MPa at 20°C for 10min. However, gram-positive bacteria still survived even by the above-mentioned pressurization at 60°C. Granule size, degradation (by hog pancreatin) and viscosity of "Nagaimo" starch were almost unaffected by pressurization less than 600MPa, being different from the results by heat treatment at 60°C and 70°C. Decrease in viscosity of water extracts from "Tororo"treated at 500 MPa or higher was suppressed as compared with that of non-pressurized ones. Browning of "Tororo" treated at 300MPa or higher was suppressed. It was supposed that polyphenol oxidase in "Tororo" was inactivated by the pressure treatment.

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Near-infrared spectroscopy (NIRS) is a very useful and powerful method to determine protein content in rice grain. Protein content estimated by NIRS was varied some factors, such as sample cells, grinding conditions, contamination of hulls, etc. But precise evaluation of the influence was not done. In this report, we described protein contents in brown rice measured by NIRS in some conditions in 1993 and 1994. The samples used were gently gifted from many agricultural stations all over Japan. The multiple regression equations established between protein contents by chemical analysis and those of NIRS gave the good multiple correlation coefficients (larger than 0.98). And also, standard errors of calibration and standard errors of prediction were smaller than 0.15% indicating the equations were satisfactory. We tested whether some factors affected or not protein contents estimated by NIRS. Difference of sample cells and measurers, and contamination of hull did not affect protein contents significantly. When powder sample was repeatedly analyzed with one packing (repeatedly used) or with repacking another part of the sample, these handlings did not either. Measurement with and without cleaning of the mill did not. Average powder size ground by different methods of grinding (different screens in Udy mill and a coffee mill) was greatly affected, but it did not affect protein content except the coffee mill. These results indicated that many factors described here did not affect protein contents estimated by NIRS.

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