Objective evaluation of coffee aroma was performed by the combination of gas chromatographic analysis and principal component analysis. (1) Arabica and robusta coffees were clearly separated by the first and second principal components and the principal components of each trade variety of coffee could be correlated with the sensory evaluation by a professional expert (cup tester) regarding to arabica coffees. (2) The blended coffees with the blending ratio of 1:1 (robusta/arabica coffee) were affected more strongly by robusta than arabica coffee. The blended coffees with the ratio of 3:1 was closely similar to robusta coffee but the coffees with the ratio of 1:3 had a quite different ftavor quality from the original coffees. (3) The good relation between a roasting degree and principal components was observed from Light to French roasted beans. Consequently, the effect of roasting on flavor formation was different between arabica and robusta coffee.

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Heterogeneous texture of cooked rice kernels of glutinous and nonglutinous rice were studied using a multi-biting test. Multi-biting test was originally developed for liquid in our laboratory, but could be applied for solid to estimate the heterogeneous texture of cooked rice kernels. Compression test and the biting test of cooked rice kernels already reported were also used to compare the texture and mothfeel and their changes on staling. Cooked rice kernels are not uniform in their texture, and the kernel of glutinous cooked rice was estimated especially soft in its exterior part compared to nonglutinous cooked rice, indicating the characteristic mouthfeel of glutinous cooked rice. Two point mensuration of biting test of cooked rice kernels also indicated their heterogeneous texture. Fracturability index was also useful for expressing the texture and mouthfeel of cooked rice kernels and their changes on staling.

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Isolates from spoiled canned foods were identified. Since many isolates did not represent typical biological characteristics as shown in text books, the simplified method was employed to identify them. Among 122 strains examined, 99 strains (81%) could be identified as follows; Clostridium sporogenes, 65; C. thermosaccharolyticum, 14; C. pasteurianum, 11; Desulfotomaculum nigrificans, 4; C. butyricum, 3 and C. perjringens, 2. Ten of 23 strains remained were identified as C. thermoaceticum, but 13 strains could not be assigned. The simplified formulae table was proposed for differential identification of commonly encountered species of genera Clostridium and Desulfotomaculum in canned food spoilage. The table enable to identify the organism according to the limited biological characteristics, i.e., optimum growth temperature, aerobic growth, morphology of a spore and a sporangium, productions of lecithinase and lipase, fermentation and digestion of milk, and production of acid from starch, production of toxin or reduction of sulfate as occasion demands.

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The isolates from spoiled canned foods were identified by the simplified method. Among 228 strains examined, 199 strains (87%) could be identified as follows; Bacillus coagulans, 56; B. subtilis, 48; B. licheniformis, 36; B. circulans, 22; B. stearothermophilus, 20; B. cereus, 8; B. macerans, 3; B. polymyxa, 2; B. pumilus, 2 and B. brevis 2. The simplified formulae table was proposed for differential identification of commonly encountered species of genus Bacillus in canned food spoilage.

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Changes in antioxidative activity of methanol extracts of germinating sesame seed and sprout was studied, and constituents considered to related to the activity were analyzed. The activity measured by thiocyanate method increased in parallel with germination, which started after 1 day incubation at 37°C, and with elongation of the sprout, 2 to 4 days after. Among the constituents, sesamin and sesamolin markedly decreased with germination, but no production of sesamol was observed. γ-Tocopherol decreased from 200 to 40μg per gram during 7 days incubation. Ascorbic acid was not detected in the methanol extract, although its amount in metaphosphoric acid extract was found to increase with germination. Total phenol content by FOLIN-DENIS method, however, markedly increased. These results suggest that the effective antioxidants in methanol extract are phenolic substances rather than sesamol and γ-tocopherol.

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The effect of the trimming which cut back the stipe end as a conventional preparation for market on freshness and composition of name-ko during storage at 20°C was studied. The trimming showed a favorable effect to prevent the elongation of stipe and the opening of cap, but resulted in higher respiration rate and accelerated browning as well as softening and squashing of the sporophore during storage at 20°C. Therefore name-ko with stipe end had some advantages for prolonging the shelf life, exhibiting suppression of browning and activation of polyphenol oxidase and protease in sporophore after harvest. Titratable acidity increased and pH declined in the sporophores stored at 20°C, but little difference was found between name-ko with and without stipe end. Trehalose was found to be predominant in name-ko at harvest and rapidly decreased during storage. On the other hand, mannitol and glucose contents increased sharply regardless of presence of stipe end. In sporophores with stipe end, trace of fructose was detected at harvest and increased reaching a maxium accumulation after 2 days of storage and then decreased, while no accumulation was found in ones without stipe end. Total free amino acid contents increased and almost doubled during storage at 20°C for 5 days, and the increase was more notable in materials without stipe end. Among the free amino acid components, remarkable increase in contents of alanine, valine, leuicine, isoleuicine, and γ-aminobutylic acid was observed during storage.

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A strain identified as Penicillium oxalicum was found to produce two kinds of triose from sucrose by transfructosylation. The characteristics of the enzyme in culture filtrate were as follows; optimum temperature was about 50°C, and optimum pH was 5. 0. The enzyme was stable below 55°C for 15 min at pH 5.0, and below pH 7.9 for 20h at 30°C. Culture conditions for production of this fructose-transferring enzyme were investigated. This strain produced the enzyme in large amount only when sucrose or isomaltulose was used as carbon source. Yeast extract or corn steep liquor was a favorable nitrogen source, while inorganic nitrogen sources were not favorable. As to inorganic salts, addition of iron (II) sulfate and manganese (II) sulfate was effective. Alternation of these factors resulted in about three times of the enzyme activity than that of basal medium.

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A novel method to determine the activation energy of moisture permeability of plastic films was assessed. A small amount of anhydrous calcium chloride was sealed in a pouch made from a packaging material whose moisture permeability was to be determined. The environmental temperature was continuously elevated at a constant relative humidity. The amount of moisture permeated was determined at suitable intervals. The moisture permeation curves were differentiated against time, and the activation energy was easily computed by equating the permeation rate to ARRHENIUS equation. The values obtained by applying this method were in good agreement with the values obtained by the conventional method using constant temperature. Using the value of activation energy thus obtained, the simulation studies on moisturing process of dried laver, Porphyra yezoensis, at varying temperatures agreed well with the experimental data.

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When the solution of egg yolk low density lipoprotein (LDL) was incubated with phospholipase C (pC) for 24h at 30°C, turbidity of the solution gradually increased and pC-treated LDL came up to the upper layer. However, the viscosity of pC-treated LDL solution was almost the same as that of native LDL solution. When pC-treated LDL was applied to TLC, the spot of phosphatidylcholine was hardly observed. In the agar gel precipitation reaction, pC-treated LDL did not give any distinct precipitin lines against anti-serum of LDL. pC-Treated LDL was well stained with Sudan III solution as compared with native LDL and it was assumed that hydrophobic component of LDL appeared on the molecular surface by incubation with phospholipase C.

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Many studies on the physiological function of dehydroascorbic acid (DHA) have been done in correlation with the redox system, but there are also papers showing that DHA reacts with cell components in the mode of action different from the redox reaction. We have had a concept that DHA possibly takes part in the control of cell growth through working directly on the cell components such as DNA. To clarify this point, we studied the effect of DHA on the growth of mouse tumor cells1)2) or callus cells3) and the action on DNA2). However, it is difficult to fix the real active principles since DHA is unstable in aqueous solution and is decomposed into various unstable intermediates. In order to make the effect clearer, it is desirable first of all to isolate the active compounds from the mixture of degradation products in the solution of DHA. This paper reports the bacterial growth-retarding potencies of the degradation solution of DHA and its fractions separated by ion-exchange chromatography.

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Spoiled canned foods were analyzed microbiologically during 1968 to 1980 in order to identify the cause of spoilage. The number of cases and samples examined was 177 and 445, respectively. The results obtained were as follows; (1) The pure cultures of causative organisms were successfully isolated from 290 (65%) of 445 samples with microbial spoilage. It was difficult to isolate the organisms from spoiled canned fruits and their juices. In these samples, the pure cultures were obtained from only 24 (34%) of 71 samples. (2) The isolates from 24 (12%) of 194 samples having swelled container's exterior failed to produce gas in subculture medium. (3) Non-spore-forming bacteria and yeast were detected in 73 (33%) of 223 samples having no defects in container's sealability. (4) Among the isolates were included aerobic spore formers obtained from 122 samples, obligate anaerobic spore formers from 76, non-spore-forming rods from 115, cocci from 12 and yeasts from 16. (5) The cause of spoilage suspected were under processing for 88 cases (49%), not thermally processed (retort bypass) for 1 (less than 1%), post process contamination for 40 (23%), incipient spoilage for 3 (2%), exposition to unusual high temperature for 4 (2%) and not assigned for 42 (24%).

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Carotenoid composition and color in peel and flesh of reddish bud mutations of Citrus natsudaidai Hayata, 'Beni amanatsu' and 'Summer red', were compared with controls, i.e. 'Natsudaidai' and 'Kawano natsudaidai'. Visually, 'Beni amanatsu' was deeper orange and 'Summer red' was more reddish orange than controls. In Hunter color values 'Beni amanatsu' peel had higher a than controls, indicating lower θ (hue) and higher saturation of color. 'Summer red' peel had higher a and lower b than controls, and thus much lower θ value. 'Beni amanatsu' was almost double in total carotenoid contents as compared with controls, but there was no difference in the carotenoid pattern itself. 'Summer red' showed no difference in the carotenoid contents, but it contained about 10% of reddish carotenoid, β-citraurin, which was not found in the controls. As for the flesh color, only 'Beni amanatsu' was slightly deeper orange and had higher carotenoid contents than others.

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