Soybean protein was hydrolyzed by 9 kinds of pretease preparations to the extent of 3.7-17.7% and used as constituents of the dried model food. The most effective antioxidative activity was found in the 17.7% hydrolyzed fraction. When soybean protein was hydrolyzed by Enzyme No.4 protease at various degrees, it was found that the higher was the hydrolysis degree, the stronger antioxidative activity was detected. The soybean protein hydrolyzates above 17% of the degree was found to decompose hydroperoxides of fat and oil. The oxidative stability of the dried model food was improved by adding soybean protein hydrolyzate above 3% level. Furthermore, synergistic effect of soybean protein hydrolyzate with d-δ-tocopherol was observed.

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The antioxidative activities of egg-white hydrolyzate with HCl and soybean protein hydrolyzates with 7 kinds of protease preparation were investigated. Egg-white hydrolyzate(hydrolyzate ratio=63.3%)showed remarkable inhibition on the autoxidation of biscuit containing lard. Especially, induction period of lard was prolonged about 325 and 400 days at 3 and 5% of addition level of the hydrolyzate, respectively. However, biscuit was turned to brown with the addition of over 1% of egg-white hydrolyzate. Hydrolyzated ratio of soybean protein by 7 kinds of protease preparations ranged from 5.2 to 21.6%. In the comparison of antioxidative activity among hydrolyzates, all hydrolyzates showed antioxidative activity on the autoxidation of biscuit containing lard at 1 and 3% level. Especially, the most effective antioxidative activity was recognized with those of 19.4-21.6% hydrolyzated ratio. However, biscuit browned by the addition of 3% soybean protein hydrolyzate but did not at 1% level.

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of miso, mutants incapable of oxidizing linoleic acid were isolated by treatment with N-methyl-nitro-N-nitrosoguanidine and the properties of the mutants were examined in comparison with those of their parents. i)The results of the effects of pH and temperature on the growth of 35 strains of the mutants showed most of them to behave similarly to their parents. ii)The mutants incapable of oxidizing linoleic acid could still oxidize glucose, fructose and ethanol, indicating that they lack specific properties for the oxidation of linoleic acid. iii)By gas-liquid chromatography, 24 strains of the mutants showed different patterns in their composition of fatty acids from those of their parents. ix)Among 35 strains of the mutants, 20 strains showed lower activity in acyl-CoA synthetase than their parents. v)From the result of examination of respiratory deficient yeasts, 12 strains of the mutants seemed to have received some changes in their respiration, not observed in normal strains.

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Brazil santos green coffee beans were irradiated with ⁶⁰Co-γ rays at doses of 0, 0.05, 0.5 and 1.5 Mrad respectively and changes of the composition of carboxylic acids in roast beans were analyzed by means of GLC together with those of the organoleptic properties of roast beans during storage by use of the cup testing. The total acid content immediately after roasting was about 6, 000mg/100g(roast beans)and the composition of carboxylic acids was as follows. Chlorogenic acid: hydroxy-carboxylic acids: mono-carboxylic acid: others=73:18:7:2. Fresh coffee flavour was influenced markedly especially in acid taste by both irradiation of γ-rays on green beans and storage of roast beans, because of the changes of above acids composition. On γ-ray irradiation, the change of the acid composition were more clear than that of stored roast beans. Therefore, the quality of γ-irradiated coffee beans seems to be closely associated with the ratio of hydroxy-carboxylic acidsmg/monocarboxylic acids mg, but little with total acid content.

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Some flavylium compounds were synthesized and their spectral behavior was studied in acidic solutions.(1)The effects of two substituent groups, hydroxyl and methoxyl of the synthetic flavylium compounds, on the wavelengths of their absorption maxima in the visible region (λ_vis.max)were examined in an 0.1% HCl-MeOH solution. Hydroxylation at the 3-position gave larger bathochromic shift than that at the 5 and 7-positions. The substitution in the B-ring (3', 4' and 5'-positions)shifted the λ_vis.max to longer wavelengths than that in the benzopyrylium ring(3, 5 and 7-positions).(2)The flavylium compounds investigated could be classified, according to their structures and spectral behavior to the pH increase, into three groups as follows: (i)with 7-hydroxy, 5, 7-dihydroxy and 8-methoxy flavylium compounds, a decrease of absorption in the visible region(flavylium salt)and an increase in the near ultra violet region(chalcone)were observed.(ii)The flavylium compounds unsubstituted in the benzopyrylium ring demonstrated a decrease of absorption based on flavylium salts and an increase due to anhydro-bases in the visible region.(iii)With the flavylium compounds substituted in the 3-position such as penonidin, a decrease in absorbance at 515nm and 272nm (flavylium salt), and an increase in absorbance at 290nm were observed.

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Using four anthocyanin pigments from Bailey Alicante A grapes and thirteen synthetic flavylium salts, the effects of two substituent groups(hydroxyl and methoxyl)on the stability of the pigment molecules have been studied in 0.2M tartaric acid-sodium tartrate buffer solutions(pH 2.5-4.5)at 50°C.(1)The pK values of the seventeen compounds investigated were determined spectrophotometrically.(2)The pigment molecules were stabilized by hydroxylation at the 5 and 7-positions in the benzopyrylium ring, and labilized by the same modification at the 3-position.(3)Since the instability of the pigment molecules increased with increasing hydroxylation in the B-ring(3', 4', and 5' -positions), it was suggested that the anthocyains hydroxylated at the ortho-position such as delphinidin-type pigments were labile.(4)The stability of the pigment molecules increased with increasing methoxylation in the B-ring.(5)From these results, it was proved that the malvidin-type pigments were the most stable.

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Changes of pnngent components in horseradish flour, mustard flour and "Wasabi" powder during storage were investigated by head-space gas chromatographic analysis using n-propanol as an internal standard. When the materials were made airtight in the vessel, the content of 4 components of allyl(R_i value), iso-propyl, sec-butyl and 3-butenyl isothiocyanates decreased. The content of these pungent components decreased as water content in materials increased during storage. These contents in the hydrolysates of the materials decreased except iso-propyl isothiocyanate during storage at 5° and 30°C. However, these hydro-lysates were quite stable at -15°C.

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In the early stage of coagulation of soybean milk by calcium ion, the turbidity of soybean milk increased linearly with a logarithm of time. Both the activation energy and the"a"factor of coagulation rate(log k=a-E/2.30RT)showed linear relationships with the concentration of calcium ion in the soybean milk.

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A New arm which magnify adhesiveness was produced for the purpose of labor saving in the measurement of textural characteristics of cooked rice by a texturometer. This new arm could reduce the measuring time to one half of that by am ordinary arm and was useful for the improvement of efficiency. Both new and ordinary arms gave almost sams results as to the relationship between texural characteristics and palatability evaluations, when some cooked rice samples were submitted to the texturometers. Therefore, it is supposed that the ordinary arm can be replaced by the new arm.

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