Volatile constituents collected by distillation under reduced pressure from Furuzuke-Takana, processed by salting of fresh Takana leaves (Brassica juncea L.) and stored for over 6 months at 2-3°C, were fractionated into acidic, phenolic, basic and neutral fractions. Among them, both of the acidic and phenolic fractions had the odors that were responsible for those of Furuzuke-Takana. The basic fraction had nearly no odor. The three fractions except the basic were subjected to the GC and GC-MS analyses, and 11 acids, 9 phenols, 8 esters, 4 alcohols, 2 carbonyls, 12 hydrocarbons, 2 sulfides, 4 nitriles and 8 isothiocyanates were identified. The changes in the relative amounts of these compounds during the cold storage of the processed Takana (Takana-zuke) were also followed. Remarkable decrease in the relative amounts of isothiocyanates and increase in those of alcohols, acids, phenols, nitriles and hydrocarbons were observed.

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During pickling in brine, the changes of Ca^-, Mg^-, K^- and Na-contents and the compositions of pectic substances consisting of the water (W-P), the hot water (HW-P), the hexametaphosphate (HX-P) and the HCl-soluble (H-P) pectin fractions in various vegetables (leaf vegetables: chinease cabbage, crisp head type lettuse; edible roots: radish root, carrot root; fruits: cucumber, ) were comparatively investigated. The results obtained were as follows: (1) The total amounts of pectic substances in the ethyl alcohol-insoluble substances (AIS) prepared from various vegetables were little changed during brining for 14 days, though the composition ratio of HX-P was markedly decreased and those of W-P and HW-P were much increased. (2) The contents of Ca, Mg and K in AIS were apparently decreased during brining, while Na increased remarkably. From these findings, it is presumed that the permiation of NaCl into tissues of various vegetables during brining causes the ion exchanges of Na with Ca Mg and K of some components in AIS including pectic substances and releases Ca, Mg and K, which give rise to the increase of W-P and HW-P, decreasing HX-P, and H-P on the contrary.

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As a part of a study on the effective utilization of waste animal blood, blood protein hydrolyzates were prepared from pig serum and erythrocytes by acid hydrolysis, and evaluated for acceptability as a seasoning. The protein contained in serum and erythrocytes could be hydrolyzed completely under the conditions applied. Heme, the undersirable pigment of blood for food materials, could not be detected in the hydrolyzate of erythrocytes, indicating that it released from hemoglobin and became insotuble by comptete hydrolysis of globin. The seasoning prepared by neutralizing the acid hydrolyzates of both serum and erythrocytes possessed good taste with slight irritating odor. However, when it was mixed with equal volume of soy sauce "shoyu", it did not affect the quality of "shoyu".

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Tofu-gels prepared from moderately heated soybean milk, expanded about 3 times by deep-frying in oil but the one excess-heated did not. The mechanism of expansion of Tofu-gels, which is also related to Aburaage-making, was studied. The main results obtained are as follows; (1) The minimum temperature for Tofu-gel expansion, was 85°C. This temperature coincides with the one for denaturation of 11S protein. (2) The failure of Tofu-gels to expand was due to the decrease of air content in soybean milk by excess-heating. The air in soybean milk was transfered into Tofu-gels and took a role of boiling centers which accelerated the vaporizing and resulted in the proper expansion. (3) When soybean milk was coagulated at high-temperature, less expansion of Tofu-gel was observed.

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The mechanism of less expansion of Tofu-gels by excess-heating was investigated. The main results are as follows; (1) The expansion of Tofu-gels was inhibited by blocking or oxidizing reagents for SH groups in soybean proteins, whereas it was accelerated by reducing reagents for S-S bonds. The facts suggest that SH groups take an important role in the expansion of Tofu-gels. (2) The Tofu-gels could not expand considerably when prepared from soybean protein solutions where either SH groups were oxidized into S-S bonds or S-S bonds were reduced into SH groups. On the other hand, Tofu-gels prepared by mixing two soybean protein solutions expanded well. It suggests that SH and S-S exchange reaction is certainly involved in the mechanism of expansion of Tofu-gels. (3) Theexpansion rate of Tofu-gels markedly decreased by heating soybean protein solution under the conditions, where the proteins easily associated or aggregated. On the contrary the expansion rate rapidly increased by mercaptoethanol or high urea concentration due to the protein dissociation. It suggests that the association or aggregation of proteins by excess-heating may prevent Tofu-gel from the expansion.

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This study was conducted to prevent inflation (swelling spoilage) of packaged foods often caused by gas production of heterofermentative lactic acid bacteria. Gas production and the growth of a heterofermenter, Lactobacillus cellobiosus Tk-1, were inhibited when the organism was grown in a mixed culture with a homofermenter, Pediococcus cerevisiae N-50. The antagonistic effect was found to be due to their competitive requirement of Mn⁺⁺ in foods. Cells in the logarithmic phase of the homofermenter, which had grown aerobically in a Mn⁺⁺ limited medium, adsorbed Mn⁺⁺ efficiently. The adsorption isotherm followed the Langmuir equation, in which the adsorption coefficient and the saturated amount of adsorption were 9.21ml/μg and 0.72μg/10⁸ CFU, respectively.

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Immobilized cells of a homofermentative lactic acid bacterium, Pediococcus cerevisiae N-50, with κ-carrageenan could adsorb Mn⁺⁺ as well as the free cells. Inflation of vacuum packaged sliced ham contaminated with a heterofermenter, Lactobacillus cellobiosus Tk-1 was suppressed when the ham extract was contacted with the free or the immobilized cells of N-50 and filtrated before packaging. The immobilized cells were wrapped with a cellulose tube to keep the free cells from gel separating from foods. Involvement of the tube including immobilized homofermenter prevented the inflation of packaged pickles, "HAKUSAI-ASAZUKE".

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When Hassaku fruit was extracted by In Line juice extractor, it is difficult to make use of soft drinks to leave Hassaku juice which has the bitterness and acidity alone, it was studied on the removal of bitterness and the reduction of acidity with ion exchange resins and adsorbents. Limonin and nomilin content of the bitterness component in Hassaku juice increased at the evaporating process and it was caused by the heat treatment. For the reduction of acidity, weak base anion exchange resins of styrene-DVB and acryl-DVB is very effective, and these resins were reduced about 50% of acidity in Hassaku juice and continuous operation is possible three hour on the column method. For the removal of bitterness, adsorbent of styrene-DVB and acryl-DVB is very effective, these adsorbents were adsorbed about 60% of naringin, 75-90% of limonin and nomilin, and continuous operation is possible for five hour on the column method.

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In order to improve the heterogeneity of the thermal reaction in a packed celite of the previously reported model roast method, which produced coffee brown pigments from chlorogenic acid and sucrose, two new methods have been designed. (1) Silica sand containing sample solutions in flasks are rotated and heated. This method is useful for the large scale preparation of brown pigments. (2) Test tubes containing small quantity of sample solution and a boiling tip are heated. This is suitable to study details of the time course of browning reaction. The results of the investigation on the first stage of the browning reaction between chlorogenic acid and sucrose by the use of latter method show the formation of coffee brown pigments A, B and C as follows: precursor brown pigment

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A new method for determination of maltol compounds in sugars has been developed. Ferric ammonium sulfate solution was added to a sugar solution to form maltol-Fe³⁺ complex. The complex was adsorbed on a silica gel column and the column was washed with aqueous sodium thiosulfate solution. The complex was then eluted with the aqueous solution of acetic acid and ethanol. Ferric ammonium sulfate solution was added to the effluent and the solution was evaporated to dryness under reduced pressure. The dried residue was dissolved with 0.05N H₂SO₄ and the solution was filtered. The absorbance of the filtrate was measured at 522nm. The determination limit was 50μg and the relative standard deviation for six determinations was 2.2%. Recoveries of added maltol from sample ranged from 98.5% to 102.5%.

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