In our previous study, semi-transparent and flexible biodegradable films were successfully prepared from myofibrillar proteins of blue marlin meat. The objective of this study was to elucidate the mechanism of film formation. Effect of pH on the amount of surface hydrophobicity and surface SH group in the film-forming solution, solubility of film proteins in various protein denaturant solutions, SDS-PAGE, and addition effect of protein denaturants in the film-forming solutions were investigated. At first, the necessity of unfolding of protein molecules was revealed for the formation of self-standing films. Secondly, the important chemical bondings involved in the protein-protein interactions were confirmed to be hydrophobic interaction for acidic condition, hydrogen bondings for neutral condition, and hydrophobic interaction and disulfide bondings for alkaline condition.

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Ume (Japanese apricot) liquor is produced from spirits, sugar and varieties of middle size Ume fruits. To examine the flavor qualities of Ume liquor prepared from varieties of small size fruits “Koume” which are generally used for “Umezuke” and “Umeboshi” (pickled Ume), we analyzed the aroma constituents, organic acids and total phenol contents in Koume liquor. Koume liquors were prepared from fruit materials harvested at immature, mature and over-mature stages of development, respectively, and aged for one year. By application of an aroma extract dilution analysis (AEDA) on each aroma concentrate of Ume liquors, total 17 peaks on gas chromatograms were detected in the flavor dilution (FD) factor range of 2 to 256. Those high FD factors revealed the following compounds as odor-active odorants in Ume liquor aroma, ethyl 2-methylbutanoate (fruity), benzaldehyde (processed Ume-like), phenylacetaldehyde (rose-like), vanillin (vanilla-like), γ-decalactone (fruity), δ-decalactone (peach-like), and γ-undecalactone (peach-like). Koume liquor prepared from over-mature fruit possessed a sweeter aroma caused by lactone compounds than other Koume liquors and a commercial Ume liquor produced from middle size fruit, however, odor-active odorants of four liquors were very similar. The contents of citric acid and malic acid in Koume liquors were influenced by those of fruit materials. The liquors prepared from immature and over-mature fruits had higher total phenol contents than commercial one. The results of sensory evaluation of three Koume liquors and commercial one suggested that these liquors were similar in the aroma and taste except of astringency. Overall, flavor of Koume liquor was acceptable as well as that of Ume liquor prepared from middle size fruit.

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Texture descriptive terms in Japanese were collected and validated. Five hundred and ninety-nine words were obtained from an open-ended questionnaire distributed to 116 food specialists in Sendai, northern area (25 individuals), Tokyo, central area (29), Osaka, western area (32) and Kagoshima, southern area (30). Out of these 599 words 332 terms were selected in a 2-day roundtable discussion made by 4 researchers. To the 332 terms added were 94 terms that have been collected from dictionaries, technical books on food texture and research papers about food texture. Thus, a list of 426 terms was presented to 55 selected assessors who had some experience of research on texture. They were asked whether these terms correctly expressed food texture. Then the data were evaluated by 4 experts who had been engaged in research on food texture or rheology for a long time. As a result of deletion and addition, 445 terms were obtained as a texture descriptive language. About 70% of the terms are onomatopoeic words. This shows onomatopoeic words play an important role in texture description in Japanese. Compared with the data taken from questionnaires in 1968, some new onomatopoeic words such as “mochi-mochi” and “puru-puru” are included in the list.

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The aim of this study was to clarify the relationship between individual personality and the subjective comfortable feeling caused by tasting chocolate. Seventeen male subjects (24.1±2.56 years old) and seventeen female subjects (23.7±3.16 years old) took the personality tests (Japanese version of the State-Trait Anxiety Inventory (STAI), the brief questionnaire for detection of type A tendency, and the Japanese version of the Bem Sex Role Inventory (BSRI)) and tasted five different kinds of chocolate, which were : 1) milk chocolate (MK), 2) chocolate with additional sweetener (SW), 3) chocolate with additional theobromine (BT), 4) chocolate with additional citric acid (SC), 5) chocolate with extract of oak wood (OK). The subjective comfortable feeling was measured by using a scale with 13 divisions, with the adjective pair of “very comfortable” and “very uncomfortable” on each end. Control (CT) was conducted by not asking the person to taste anything. The results were as follows : In the female subjects, 1) The comfortable feeling was significantly higher than that of the male subjects, especially in BT. 2) The masculinity and the femininity had significant positive effects on the comfortable feeling. In the male subjects, 1) The type A tendency had a significant positive effect and the trait-anxiety had a significant negative effect on the comfortable feeling. By investigating the relationship between personality and comfortable feeling in each kind of chocolate, 1) The femininity of the male subjects and the comfortable feeling of OK, and 2) The masculinity of the female subjects and the comfortable feelings of OK and SW showed significant correlation. It is considered useful to investigate people's personalities when discussing individual differences in chocolate preference.

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As Honkakushochu is a type of spirits, the taste components such as sugars and amino acids are not included. However, the general terms expressing tastes, such as “sweet”, “bitter” or “Umami”, are used as the evaluation. We reported the possibility of use of taste sensor as one of the technique which evaluate the taste of Honkakushochu. In this report, the investigation that combined the sensory evaluation with the chemical analysis was done (to select sensors that identifies basic taste of Honkakushochu). Ethanol mainly showed the bitterness accompanied by a feeling of a stimulus (at 15-18% of ethanol concentration by which Honkakushochu is generally drunk). From the results which identified the sensor which responds to the taste of ethanol of Honkakushochu preferentially, it was shown that the sensor which was used tetradodecyl ammonium bromide, tetradodecyl alcohol (TDA) for lipid/polymer membranes and was used dioctylphenyl phosphonate (DOPP) for plasticizer, responded to ethanol concentration well. Moreover, from the results which identified the sensor which responds to the sourness of Honkakushochu preferentially, it was shown that the sensor which was used phosphoric acid di-N-decyl ester for lipid/polymer membranes and was used 2-nitrophenyloctyl ether (NPOE) for plasticizer, responded to the sourness well, and that the correlation with sensory evaluation was high.

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The Japan Agricultural Standard (JAS) law revised in 1999 requires correct labeling of species and origin of marine products. We developed methods for identifying three Sparidae species, Red seabream (Pagrus major), Crimson seabream (Evynnis japonica) and Yellowback seabream (Dentex tumifrons) by PCR-restriction fragment length polymorphism (PCR-RFLP) and multiprimer-PCR using species-specific primers. PCR-RFLP analysis of the 498-bp DNA fragment amplified from the mitochondrial cytochrome b gene of three Sparidae species that were digested by two restriction enzymes, SspI or StuI, showed species-specific restriction fragment patterns for these species. To simplify the Sparidae species identification, we also carried out multiprimer-PCR analysis using species-specific primer set based on unique nucleotide substitutions in each species, and showed usefulness of this technique for Sparidae species identification.

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Although heat sterilization is commonly used to sterilize polysaccharides to be used as a food additives, it is difficult to sterilize heat-resistant bacteria even by heat sterilization method and heat sterilization causes changes of physical properties and color tone in appearance of polysaccharides. It is thus required to develop novel non-heat sterilization method that causes no changes in physical properties of polysaccharides. We investigated effects of electron beam irradiation on physical properties of polysaccharides. Electron beam irradiation mostly caused decrease of average molecular weight, leading to the decrese in viscosity and gel strength. Magnitude of changes in these physical properties depended on polysaccharides. It was also found that physical properties of gum arabic were hardly changed by electron beam irradiation. We discussed some factors causing difference in physical properties of polysaccharides by electron beam irradiation in terms of the properties of polysaccharides.

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Using various tea-leaves, fermented tea (Hakkohcha) was newly prepared, which is referred to as “post-fermentation tea”. As the result of sensory evaluation, no significant difference was seen among between likes and dislikes. To examine the protective effect of the new fermented tea on carbon tetrachloride (CCl₄)-induced acute hepatic injury in rats, the serum GOT and GPT levels were measured and pathological changes were examined. Elevation of GOT and GPT serum levels induced by carbon tetrachloride treatment was significantly suppressed by pre-administration of the new fermented tea. Furthermore, the pathological damage was also reduced. The most effective reduction was observed when the tea was orally adminiatered 30 min before the CCl₄-treatment.

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