An emission of ultra weak chemiluminescence (photon) in the presence of active oxygen species (X), active oxygen scavenging substances (Y) and receptors (Z) have been found as XYZ-system by Yoshiki et al. We established a new antioxidative activity assay, XYZ-dish method, which was applicable for various foods and materials, after the investigation with several quantitative conditions. The important points for measurement were as follows; using gallic acid (GA) or foods as Y sample, 50mM phosphate buffer (pH 7.0) containing 441mM hydrogen peroxide (H₂O₂) as X and 1136mM acetaldehyde as Z/MeOH=50:50 as a reaction solution, and sample dish of stainless steel adaptable for easy measurement of various kinds of food. The photon emission was quantitatively measured by injection of 2ml of reaction solution into 1ml of GA solution in the dish taking the measurement time for 2min from injection start. By the addition of FeCl₂ to this assay system, photon emission of GA against hydroxyl radical (⋅OH) as X was also measured. However, treatment of food samples containing Fe²⁺ was left for further improvement. Furthermore, photon emission dependent on sample weights was quantitatively detected by XYZ-dish method using homogenates of blueberry and natto as Y sample, which were solid type of foods. These results showed that XYZ-dish method was useful as a new antioxidative activity assay for various foods against H₂O₂ and ⋅OH by measurement of photon and comparison with GA as a standard antioxidant.

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Shiitake mushroom [0Lentinus edodes (Berk.) Sing.] was cultivated on sawdust medium to which had been added okara, the insoluble residue of homogenized soybean (the waste product of tofu manufacture), rice bran and corn bran at concentrations of 5, 10, 15, 25 and 35%, respectively. Total nitrogen in the medium and fruit bodies cultivated on the sawdust medium was determined. Fruit bodies were analyzed for total amino acids, amide-N, free amino acids, nucleic acids and chitin. Nitrogen content of fruit bodies cultivated on sawdust medium was closely related to that in the medium. Nitrogen content of the sawdust medium was related to amino acid, nucleic acid and chitin contents. No significant relation between lentinic acid in fruit bodies and nitrogen content in the medium was observed. The amount of lentinic acid in fruit bodies cultivated on sawdust medium containing rice bran and corn bran was about 2 times that cultivated on okara-added medium. Nitrogen content of fruit bodies is thus shown to be affected by nitrogen sources present in the medium. High levels of nitrogen in sawdust medium should decrease carbohydrates in fruit bodies cultivated on the medium, thus making the fruit too soft for eating.

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Fifty-three onomatopoeic terms for describing food properties were characterized through two kinds of questionnaires by a laboratory panel of 31 members. In the first questionnaire, panel members evaluated the relationship of these terms to such food properties as the appearance, aroma, taste, temperature, sound and texture under a total point of 10; If a term corresponds to one property, the property is 10, and if one relates to any properties, the points are distributed according to their degree of association. Fifty-three terms were classified into 14 groups on the basis of t-statistic calculated from mean and standard deviation of points evaluated by 31 members. All the terms were linked with a single property or two, and 43 of them were found to be expressions related to texture. The terms related to sound were always associated with texture. On the other hand, there were some terms related to two inhomogeneous properties, such as "mattari", which was related to taste and texture, "doro-doro" appearance and texture. In the second questionnaire, the panel members listed the kinds of foods they imagine from each term. The data were analyzed by Quantification Method III. The terms and foods were plotted on the plane coordinates with "brittleness" taken as ordinates and "elasticity" as abscissas. Thus, the relation between each terms and foods was quantitatively presented.

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This study was undertaken to determine the effects of temperature and pH on the degradation of gonyautoxin (GTX) 1-4 in both canned oyster infested with paralytic shellfish poison (PSP) and a model GTX 1-4 solution. The degradation of GTX 1-4 in the model solution obeyed good first order kinetics over the entire range of temperature (80-120°C) and pH (6.0-8.0) used in the experiment. The degradation rate of GTX 1-4 increased with the rise of temperature and pH with the correlation coefficient ranging from 0.87 to 0.98. These results obtained with GTX 1-4 in the model solution were almost the same as those with GTX 1-4 in heated-canned oyster infested with PSP. Thus, the amount of GTX 1-4 remaining in canned oyster after heat treatment can be estimated by prediction equations derived in this study.

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To make a good use of rice bran that has been treated as a kind of industrial waste, we have tried to ferment the rice bran by typical microorganisms such as yeast, and to extract ingredients with antioxidative activity. The antioxidative activity was estimated as a SOD-like activity. The SOD-like activities of the rice bran extracts after fermentation by using ESR spectroscopy by baker's yeast and whisky yeast significantly increased in comparison with that of rice bran extract without fermentation. The components in the rice bran extracts after fermentation participating in the SOD-like activity were suggested to be kinds of protein. We estimated the molecular weights of the proteins precipitated with ammonium sulfate, using a HPLC. Based on the results obtained from the HPLC measurements, the proteins with a SOD-like activity various molecular weights exist in rice bran extracts after fermentation. The proteins with a SOD-like activity may be composed with the other components such as polyphenol and sugar, having a SOD-like activity.

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We have prepared zein peptides and characterized their ability to regulate the activity of cyclic nucleotide phosphodiesterase (PDE) isozymes obtained from canine heart ventricle. Native-zein inhibited 42%, 18%, and 25% of the activities of PDE1, PDE2, and PDE4, respectively. AT1 was prepared by partial hydrolysis of the native-zein with 0.3N HCl at 50°C for 24hr. The AT1 increased the activities of 63% and 40% of PDE1 and PDE4. AT1 was hydrolyzed with pepsin, chymotrypsin, thermolysin, and subtilisin. Pepsin-and chymotrypsin-treated AT1 increased the activity of PDE1 by 75%. Deaminated-zeim were prepared by mild HCl hydrolysis (with 0.2N HCl at 55°C for 5hr). Deamidation of zein had no effect on the activities of PDE1, PDE3, and PDE4. However, a deaminated-zein fraction (DA-3) increased PDE2 activity by 16%. From these results, it was confirmed that zein peptides had regulatory effects on PDE isozymes.

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An acid and sugar content analyzer (NH-1000, HORIBA Ltd.), for citrus fruit based on the conductometric method (acid) and on the refractometric method (Brix value), is put to practical use. To develop a simple method for measuring free organic acid concentration in tomato and strawberry juice, the accuracy of this equipment and the effects of some major compounds in these juice on analyzed values were studied. The values measured for tomato and strawberry juice by this equipment were higher than the titratable acid. Especially tomatoes with blossom-end rot showed very high measured values of acid content. It is considered that the acid content of tomato and strawberry juice obtained by the acid and sugar content analyzer need to be corrected using calibration equations, and that tomatoes with blossom-end rot should be removed before analysis. The organic acid composition of fruit juice varied slightly among tomato, strawberry and Satsuma mandarin samples, but the differences in conductivity of organic acids or the errors in the conversion factor for titratable acidity were not considered to be the main causes for the difference between titratable acid and the measured acid value by the acid and sugar content analyzer. The main positive element in all fruit juice samples was potassium, whereas the main inorganic anions were phosphate and chloride ions in tomato and Satsuma mandarin, and phosphate, chloride and nitrate ions in the strawberry sample. The difference between the measured acid values by the acid and sugar content analyzer and those by alkaline titration is highly correlative to both the positive element and anion concentrations in the fruit juice.

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To improve the quality and increase the yield of thick bean sprouts, and to expand their usage, we cultivated thick mung bean and soybean sprouts by dipping intermittently in mixed phytohormone solution in combination with irradiation of artificial sunlight lamps (DPSL method). Concerning growth, the extension of the hypocotyl and the main root and the number of lateral roots were markedly inhibited in both types of bean sprouts. The hypocotyl was hypertrophied, and the hardness and the mastication degree increased, fulfilling the suitable qualities for marketing. Thus, the external appearance was improved. The surface color of the hypocotyl was pale yellow to light yellowish green in both types of thick bean sprouts. This color provided additional value such as their use for salads and other dishes as a colored vegetable. The moisture content was inadequate for both types of bean sprouts, resulting in lacking of juiciness. The yield was also insufficient for both types. Among the components, protein and sugar increased while fat decreased in both types of bean sprouts. With cultivation days, the content of water-soluble vitamin except VB₁ increased in both types of bean sprouts. Though the VB₁ content tended to decrease, its content was higher than that in the control. Chlorophyll was not present in either type of bean sprouts on day 1-2 of cultivation but was produced from day 3 and markedly increased with cultivation days. In mung bean sprouts, carotene was not present in the control and was produced from day 3 of cultivation. In soybean sprouts, a very small amount of carotene was present at the time of inoculation (germination). In both types of bean sprouts, the carotene content increased from day 3 of cultivation, but the degree of the increase was slight compared with chlorophyll. The DPSL method inhibited growth and improved the composition and external appearance. Application of artificial sunlight lamps induced color in the hypocotyl and increased the nutritional composition by producing chlorophyll and carotene. These changes improved quality, expanding their usage. However, the decrease in the yield due to the inadequate moisture content is economically disadvantageous. Furthsr studies on cultivation conditions are necessary

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Two kinds of fish sauce ISHIRU made from squid liver and sardine are produced in Noto peninsula of Ishikawa prefecture. This ISHIRU, as well as SHOTTURU in Akita and IKANAGO SYOYU in Kagawa, is very famous as one of three major fish sauces in Japan. In this study, free amino acids, oligopeptides, organic acids, nucleotides of ISHIRU were analyzed, and their characteristics related to the taste of ISHIRU were discussed. The results were as follows: (1) ISHIRU contained large amounts of total nitrogen and salt. (2) The major organic acids of ISHIRU were lactic acid, pyroglutamic acid, acetic acid, formic acid, succinic acid, malic acid and so on. (3) ISHIRU contained large amounts of free alanine, glutamic acid, glycine, lysine and valine. (4) The constituent amino acids of oligopeptides in ISHIRU were glutamic acid, glycine, aspartic acid and lysine. (5) Adenosine-5'-monophosphate (AMP), inosine-5'-monophosphate (IMP) and guanosine-5'-monophosphate (GMP) were not detected in ISHIRU. From these results, it is presumed that the characteristic taste of ISHIRU is extensively related to the contents and proportions of free amino acids, oligopeptides and organic acids, but nucleotides hardly contribute to its taste.

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Removal of protecting group from an aspartame precursor (ZAPM) by hydrogenation with palladium supported on activated carbon was carried out. No precipitation of APM occured when methanol/water mixture with volume ratio of 65/35 was used as a reaction solvent, and ZAPM was mostly converted to APM by hydrogenation. After the separation of the catalyst by filtration, APM precipitate could be obtained by cooling of the solution. Ethanol and ZAPM paste could be used instead of methanol and ZAPM powder, respectively. By preventing APM precipitate formation during the hydrogenation, simplification of APM production process was achieved.

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Tencha is a kind of processed tea leaves which is used as material for powdered tea, Matcha. To estimate the quality of Tencha with storages in air and in nitrogen at 5°C for 6 months, vitamin C, chlorophyll and its related derivatives contents and the stability of chlorophyllase activity in Tencha leaves were investigated. The residual rates of the apparent total vitamin C and ascorbic acid in Tencha were about 80% in air and 90% in nitrogen after 6 months of storage, respectively. The apparent oxidized vitamin C remained constant during 6 months. Surface color (-a/b value) of Matcha (powdered Tencha), and contents of chlorophyll and its related derivatives in Tencha varied very little in both atmospheric conditions after 6 months of storage. Though chlorophyllase remained enough activity to react after 6 months-storage of Tencha, the enzyme did not cause the degradation of chlorophyll in Tencha under the storage condition of low moisture. These results indicate that Tencha have maintained satisfactory quality during the 6 months-storage in air at 5°C for aging to favorable Matcha.

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A novel method for the determination of freshness of rice was developed. This method is based on the acidification power test for analyzing of metabolic activity of yeast cells. Acidification power was given as the difference of spontaneous pH change between determined after suspending rice in water and substrate-induced pH change after addition of glucose to the resulting suspension. The value of acidification power of fresh rice (Akitakomachi) was 1.6-fold higher as compared to that of old rice that was stored for one year at 15°C. It was considered that the acidification power test was used for an indicator of freshness of rice.

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We made Sainte-Maure type cheese from pasteurized goat's milk and ripened it at 12°C and 93% relative humidity. The number of starter lactococci was approximately 5.8×10⁸ per gram of cheese in the beginning and decreased to 4.1×10⁷ at the 31st day of ripening. It was confirmed that goat's milk cheese differed from cow's milk cheese made under the same conditions in the pattern of protein degradation. The total free amino acid and the total free fatty acid contents increased remarkably after 10 days of ripening. Judging from the extent of proteolysis and lipolysis and from the results of a sensory test, the optimum ripening period seemed to be 15-20 days after the start of ripening under the present conditions.

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Egg yolk low density lipoprotein (YLDL) had a growth stimulating activity to a human monocytic cell line UM. Analysis on binding of YLDL labeled with europium (Eu) to the UM cells by time-resolved fluorometory showed that UM cells had a large number of binding sites with low binding affinity on the cell surface. Inhibition analysis of the binding by using human serum lipoproteins suggested the binding site would have an affinity to human very low density lipoprotein.

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