The properties of cooking flavors of chicken fractions such as lean meat, skin and adipose tissue were investigated. The flavors were evaluated with sensory test, gas chromatography, the amounts of hydrogen sulfide (H₂S) and volatile reducing substances (VRS). The cooking flavor of chicken lean meat was best and it was intensified by blending with skin or adipose tissue. The strongest chicken flavor and a large amount of H₂S and VRS were produced from the water soluble protein (sarcoplasmic protein) fraction of all the protein fractions of lean meat. Chicken like aroma and a small amount of H₂S and VRS were also produced by cooking of the salt soluble protein (myofibrillar protein) fraction and the stroma fraction. Therefore, it may be assumed that these protein fractions also contribute to the production of cooking flavor of chicken. The strength of chicken aroma and the amount of VRS produced during cooking were decreased by defatting of the lean meat and the skin. It was confirmed that taste substances were retained in the aqueous fraction of chicken broth and aroma substances in the oil fraction. These results suggested that the combined use of these two fractions was reasonable for the seasoning manufacture.

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We reported that reductones were produced during the preparation of malt or koji extract and the amount was increased by sterilization thereafter. In this paper, the effects of the reductones on 10 strains of Saccharomyces sp. are described. Triose reductone (TR), L-ascorbic acid and reductic acid were employed in the range of 1.0×10^-2M to 1.0×10^-4M. Among these reductones, only TR showed an significant effect on the fermentation by yeasts, especially by Saccharomyces carlsbergensis. At concentration of 1.0×10^-2M of TR, both growth and fermentation were suppressed. The cell free extract of Fleishmann yeast for bread making showed the same effect. In the experiments employing TR and dehydro TR, only TR affected the fermentation of Sacc. carlsbergensis.

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Strawberry homogenate (pH6.5) was prepared by blending strawberries with two times as much of 0.2M phosphate buffer (pH7.5) in an ice bath. Five ml of 0.1M α-keto acid-Na was added to 5ml of strawberry homogenate in a 20ml vial vessel, and was sealed with a silicone rubber septum. After 2hr incubation at 25°C, 3ml of vapor sample was taken out through the silicone rubber septum by means of a gas-tight syringe and analyzed by gas chromatography (GC) and GC-mass spectrometry. All α-keto acids examined (e.g., pyruvic, α-keto-n-butyric, α-ketoisovaleric, α-keto-nvaleric, α-ketoisocaproic and α-keto-n-caproic acids) were converted to aldehydes (e.g., acetaldehyde, propionaldehyde, isobutyraldehtde, n-butyraldehyde, iso-valeraldehyde and n-valeraldehyde). The optimum reaction pH was between 6.0 and 6.5. This reaction is assumed to be attributed to pyruvate decarboxylase (2-oxoacid carboxy-lyase; E.C. 4.1.1.1) on the ground that the addition of thiamine pyrophosphate and/or Mg²⁺ enhanced the formation of aldehyde. The addition of alcohol dehydrogenase from strawberry seeds to the reaction mixture together with NADH resulted in the simultaneous production of aldehyde and alcohol from α-keto acid. In this paper, the pathway from α-keto acid to ester in strawberry is briefly discussed based on the all the results obtained in the present examination and from our previous reports.

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Kinu-tofu coagulated with GDL (glucono-delta-lacton) is harder than that coagulated with calcium sulfate, but it is more fragile. In order to study these cause, effect of NEM on hardness of the tofu-gels and effects of urea, mercaptoethanol and EDTA on solubility were investigated. The effect of NEM on hardness of the tofu-gels shows that disulfide bond has important role on gel formation of GDL-tofu-gel as well as Ca-tofu-gel. The effects of urea, mercaptoethanol and EDTA on solubility of the tofu-gels indicate that GDL-tofu-gel and Ca-tofu-gel are formed by disulfide, hydrogen and hydrophobic bond, and that Ca-bridge has also an important role on Ca-tofu-gel.

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Tofu-gel prepared with soybean milk which was heated at 100°C for long time, was softer than usual preparations. This is due to the oxidation of sulfhydryl groups of soybean protein during the heating. Blowing nitrogen gas into soybean milk before heating increased the hardness of the gel by preventing the oxidation of sulfhydryl groups. Protein solution immediately cooled to 60-70°C had much more sulfhydryl groups than that cooled to 80-90°C, and the tofu-gel prepared with the former protein solution was harder. Soybean milk obtained by filtering the mash heated at 60-80°C, was higher in yield than that obtained from the mash heated at 100°C or unheated. From these experimental results reasonable heating process of soybean milk for tofu making are as follows, after heating mask at 70°C, filter it to get soybean milk, heat the soybean milk at 100°C and cool to 70°C for coagulation.

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Plant growth regulators, indole-3-acetic acid (IAA), kinetin (KIN) and gibberellic acid (GA₃) were examined in different concentrations to estimate the effects on mycelial growth of L. decastes. In the liquid still cultures containing various concentrations of IAA, KIN and GA₃, observation on the mycelial growth on surface of media were carried out for four-month incubation. The mycelial growth was enhanced in the cultures containing 1ppm of IAA, 10ppm of KIN and 1ppm of GA₃ respectively. Incubations in the media containing higher levels of growth regulators showed some inhibition of mycelial growth. The mycelial growth was not observed in the media containing over 500ppm of IAA and KIN.

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Amino acids (L-Val, L-Lys·HCl, L-Asp, L-Phe, L-Pro, DL-Met) were heated separately with D-glucose at 120°C, for 120 minutes in homogeneous powder state. The reaction mixtures were dialyze and nondialyzed portions (non-dialyzable melanoidins) were analyzed for amino acids after hydrolysis (6N HCl, 110°C, 18hrs). Considerably large amount of original amino acid and ammonia were found in hydrolysates. Thus, it was assumed that non-dialyzable melanoidin contained original amino acids, amino-radicals formed through deamination and acid amides presumably formed from oxydized glucose. Other amino acids and ninhydrin-positive substances were detected. IR spectra of non-dialyzable melanoidins were also measured.

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