In the previous papers, we reported that dispersions of chicken muscle and carp muscle proteins exhibited spinnability, following the addition of either a free fatty acid, the anionic surfactant, and that such dispersions exhibited increased shear stress and the loss modulus/storage modulus ratio. In the present study, we investigated the effect of oleic acid (OA) on fiber formation by chicken, cod and ox liver protein dispersions, and the OA and lysinoalanine (LAL) content and the microscopic configuration of the resulting fibers. Protein fibers were obtained by extruding these protein dispersions with an OA addition of 15% per protein, at pH 12 and 40-50°C into coagulating baths through spinnerets (0.1mm diameter). No protein fibers were obtained when OA was not added. The freeze-dried cod protein fiber was found to contain 80% of the added OA, and 85mg of LAL per 100g protein. The toughness of all of the animal protein fibers were larger than that of soybean protein fiber. Electron microscopic observation of the cod protein fibers showed them to be oriented lengthwise and to have a diameter of 500-700Å, thus lying between that of myofibril and myofilament.

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Ripening of 'Sordum' plum fruits is suppressed when stored at 30°C. The effect of ethephon treatment on the fruits stored at 30°Cwas investigated to clarify whether ethephon can induce ripening. The fruits were dipped for 5min in the solutions of 300ppm or 600ppm ethephon. Climacteric patterns in respiration were not observed in the treated fruit but carbon dioxide production was increased by ethephon treatment. The pulp of ethephontreated fruit softened more rapidly than that of untreated fruit.The peel of treated fruit turned red, but the flesh remained pale yellow. Phenylalanine ammonia-lyase activity in the flesh decreased gradually during storage. The rates of softening and peel color development of 600ppm ethephon-treated fruit were higher than those of 300ppm ethephon-treated fruit. No significant differences in titratable acidity or sugar content between treated and untreated fruits were found.

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The juice oil of sudachi (Citrus Sudachi Hort. ex Shirai) was prepared by simultaneous distillation-extraction, and separated into fractions of hydrocarbon and oxygenated compounds through a silica gel column. Both fractions were analyzed by gas chromatography (GC) and combined gas chromatograph-mass spectrometer (GC/MS). The volatile components including 26 hydrocarbons, and 74 oxygenated compounds, were identified by GC/MS and Kovats Indices. Comparing with the oxygenated components of the peel oil, the juice oil mainly consisted of α-terpineol, decanal and dodecanal. Twenty nine components including unsaturated aldehydes such as (E)-2-heptenal and (E)-2-octenal were identified in the juice oil. These were not found in the peel oil. As the oxygenated fraction had the characteristic aroma of sudachi juice, this fraction was further separated into four fractions. Fraction 1 having characteristic aroma of sudachi juice was examined by GC/MS and GC-Sniffing. It was suggested that aliphatic aldehydes and esters such as decanal, dodecanal and octyl acetate, might contribute to the sweet aroma of sudachi juice.

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ω-Methylthioalkyl and ω-methylsulfinylalkyl isothiocyanates have been known to contribute to the characteristic flavor of fresh wasabi. We studied on the change and stabilization of these compounds during freeze concentration of freeze-milled wasabi and horse radish. ω-Methylsulfinylalky1 isothiocyanates are possibly produced by enzymecatalyzed oxidation from ω-methylthioalkyl isothiocyanates and/or ω-methylthioalkyl glucosinolates in wasabi. We discussed on suitable enzyme reaction conditions for wasabi and reasonable biosynthetic pathway of ω-methylsulfinylalkyl isothiocyanates in it.

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Proteolysis in fermented sausage during ripening was investigated. After 4 weeks-incubation under a high moisture condition such as vacuum-packing, the total amounts of free amino acids in sausages reached 466μmol/g dry matter. This was equal to the value attained by 6 months-incubation under drying condition. From the analysis of free amino acid compositions and SDS-polyacrylamide gel electrophoresis of whole proteins, it was considered that the enzymatic reaction rates did not appreciably decreased under a high moisture condition, so that proteolysis of meat proteins was greater than under drying conditions.

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Chum salmon during spawning migration, called Bunazake in Japan, has not enough taste and protein suitable for conventional fish products and therefore, the new processing of Bunazake has been required to use them as one of possible food protein resources. Bunazake muscle was heated by boiling and removed its excess water with a single screw press to make Bunazake flake, and then examined its transformation to a texturized fish product with a twin-screw extruder. The extruder used in this study was a fully intermeshing co-rotating twin screw type equipped with a cooling die or a molding unit (Mitsubishi FT 60-N, screw diameter 60mm, L/D=20). There were some difficulties to texturize Bunazake flake to continuous fibrous products with the cooling die. However, 10% addition of wheat flour enabled the continuous extrusion cooking of Bunazake flake and enhanced the fibrous protein matrix formation in the extrudete, accompanying the reduction of extrusion pressure. The molding unit was found suitable to make large extruded meat lump regardless of the material composition. The microstructure and breaking strength of the extrudates revealed that the added wheat flour was distributed into the protein matrices to prevent them from fusion, and improve the alignment of fibrous fish protein matrix. These results suggest that the addition of other component such as wheat flour is one of possible means to control the formation of protein matrix and its alignment in the extrudate. SDS-PAGE showed that the addition of wheat flour enhanced the reduction of solubilty of Bunazake muscle protein. It is likely that wheat flour promotes the formation of cross-linking of proteins such as isopeptide bonding, a condensation reaction, by holding the water produced through the reaction.

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'Cavendish' banana (Musa sapientum L) fruits were treated with ethylene for 1 day and held for 2days at 20°C. These greenish yellow banana fruits were packaged hermetically in polyethylene bags (0.03mm thick.) with or without ethylene absorbents and stored at 12°C and 20°C. The shelf life and the change of volatiles production of the fruits were investigated. During the storage at 20°C, the fruits packaged in perforated polyethylene bags became full yellow in 3days, and lost salability in 6days due to occurrence of brown flecks developing to entire browning. Polyethylene packaging completely inhibited the occurence of brown flecks regardless of ethylene absorbents and prolonged the shelf life. Water-soaked injury, however, happened in sealed bags 10days after packaging, though ethylene absorbents delayed this injury 5 more days. O₂ concentrations were 1-2% and CO₂ concentrations were about 10% in the bags with or without ethylene absorbents at 20°C. The production of isoamyl acetate and iso-butyl acetate, characteristic banana flavor volatiles, increased quickly in the fruits in perforated bags at 20°C. In the fruits packaged in sealed bags, the production of these compounds increased slowly at early periods, but marked increase followed at later periods especially in the packaging with ethylene absorbents. Productions of ethyl alcohol, acetaldehyde and ethyl acetate increased quickly in the sealed bags with or without ethylene absorbents, in spite of limited increase of these volatiles in perforated bags at 20°C. They, howewer, decreased gradually at later periods in the packaging with ethylene absorbents. At 12°C, disappearance of green in peel were insufficient throughout the storage period and water-soaked injury occurred after 15days in both hermetically sealed and perforated bags. Volatiles production was markedly lower than that at 20°C with an exeption of butyl acetate.

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It was demonstrated that the browning of 'yuzu' (Citrus junos Tanaka) juice was brought about by several other components aside from L-ascorbic acid (AA). Addition of higher levels of furfural (FUR) or 5-hydroxymethylfurfural (HMF) brought about enhanced browning in the presense of juice components such as AA, amino acids and glucose. It was, however, observed that FUR and HMF had no effect on the browning, when those levels in the juice were less than 10mg/100ml and 0.5mg/100ml, respectively. In juice stored for 18months at 37°C, AA degraded completely, and FUR and HMF occurred at 0.5mg/100ml and 22mg/100ml, respectively.

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One hundred five colonies were isolated as 5, 5, 5-trifluoro-DL-leucine resistant strains from Zygosaccharomyces rouxii KS by ethylmethanesulfonate treatment. Four strains producing higher amounts of iso-butyl and iso-amyl alcohols than the parent strain were selected from the resistant strains. Barley miso fermented by T-10, one of the selected strains, contained higher concentrations of iso-butyl and iso-amyl alcohols than that by the parent strain.

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The thermal degradation of anthocyanins, in a pigment solution extracted from thelyophilized powder of eggplant peel with 0.1% hydrochloric acid-methanol and in the powder itself, was examined. The anthocyanin retention with time was measured at 50°C and 60°C in the former sample, and at 100°C and 120°C in the latter sample. Thekinetic data(k, ΔG^≠, Ea, ΔH^≠, and ΔS^≠) on anthocyanin degragation were obtained. The thermal decomposition of total anthocyanins including nasunin in 0.1% hydrochloric acid-methanol solution seemed to proceed as a first order reaction. The reaction was reproducible. The scattering light in a laboratory did not considerably influence upon the rate of nasunin degradation. In case of the lyophilized powder, the reaction seemed not to be a first order one. There was little difference between the decomposition rates of total anthocyanins heated at 100°C and at 120°C for 60min, however, the great increase in the rate of nasunin at 120°C was observed.

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The correlations between sensory and instrumental textural qualities of fish muscles were investigated using raw and cooked samples of three fish species (Skipjack, Yellowtail, Yellowfin tuna). The force induced by the columnar plunger at strain=50% and the elastic modulus at large strains (30-70%), correlated with sensory att ribute of "Firm-soft" in raw and cooked muscles (P<0.01), while the penetration depth of needle, the force induced by the columnar plunger at strain=50%, and the elastic modulus at large strains (30 and 70%) correlated with sensory attribute of "Wet-dry" (P<0.01). The macrostructure of muscle, especially the myoseptum, affected the result produced by plate-shaped plunger, and the correlation between the force at strain=50%and the sensory attributes of "Firm-soft". and "Wet-dry" was significant at P<0.05 level but not significant at P<0.01 level. The creep curves were analysed by a five-element and four-component model. The R1 component represented the recoverable instantaneous deformation. The R2 component represented the recoverable Voigt model. The P component represented the non-recoverable instantaneous deformation plus the non-recoverable Voigt model. The N component represented the Newtonian viscous flow. When these fish muscles were cooked, the combination of R1+R2 increased and P decreased in percentage expression. This result means that the main contributor to total deformation was plasticity (P) in the raw muscles but was elasticity (R1+R2) in the cooked muscles. The R1 component in percentage expression correlated with sensory attributes of "Elastic-plastic" and "Compact-flaky" at P<0.05 1evel. In all sensory attributes, the cooked muscle of yellowtail was extremely different from the cooked muscles of sklpjack and yellowfin tuna. This difference is partly due to the high lipld content of yellowtail muscle.

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