In order to prepare soymilk containing a high amount of calcium equivalent to cow's milk (25mM), the effects of the addition of calcium salts on the colloidal stability of 7S or 11S-globulin containing solution and soymilk prepared commercially were investigated by the measurements of relative viscosity, soluble nitrogen (soluble protein) and pH. The main results obtained were as follows: (1) When various calcium salts such as calcium chloride, calcium sulfate, calcium citrate and calcium phosphate were added to the solution containing 0.1% of 7S or 11S-globulin and to the soymilk, calcium chloride was most sensitive as compared with other salts, followed by calcium sulfate, calcium citrate and calcium phosphate in decreasing order of sensitivity. (2) Colloidal stability of 7S or 11S-globulin containing solution in the presence of calcium salts was increased with an increase of pH in buffer solution. (3) Soymilk containing disodium hydrogen phosphate (20mM) or sodium citrate (20mM) did not show any precipitation even when 19mM of calcium chloride was added to the milk. In the case of inorganic phosphates, it was found that the stability of soymilk in the presence of calcium salts was raised with increasing chain length of the phosphates. (4) Calcium fortified soymilk (19mM calcium chloride added) containing sodium citrate (20 mM), disodium hydrogen phosphate (20mM), sodium pyrophosphate (15mM) or sodium tripolyphosphate (10mM) were highly stable without any sign of precipitation and coagulation at 4°C for 7 days.

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The violet pigment producing bacteria was isolated from Yudemen and identified. Protection of Yademen against microbiological deterioration were also investigated. The results obtained were as follows: 1) The necessary pigmentation conditions for the isolated microorganism are temperatare withen 5-25°C using mannit yeast extract medium at pH 5-8 and aerobic culture. Best growth of this microorganism occurred at lower temperature (5-10°C) with aerobic condition. 2) The microorganism isolated from spoiled Yudemen was identified as Janthinobacterium lividum based on the biological properties of type culure. 3) The isolated J. lividum has been sterilized by heating for 10min at 70°C. There was a significant difference in ozone germicidal effect of isolated J. lividum between initial stage of ozone treatment (10min) and subsequent stage (60min). The D value of 1.70min was determined with former, whereas the latter had a value of 5.00min.

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Violet pigment isolated from Janthinobacterium lividum was identified tentatively as violacein by spectrophotometric method. The absorption maximum of the pigment in 99.5% ethanol solution was 579nm and the minimum was 430nm. The violet color of this pigment discolored to green by acid and reddish brown by alkali. The antimicrobial activity of the pigment was investigated on 21 bacterial strains, encompassing 18 species in ranging from 20 to 200μg/10ml. The pigment was ineffective on 5 gram negative strains (4 species) and 1 strain of Bacillus (B. subtilis var. natto). The growth of Bacillus (11 strain, 8 species) and Micrococcus (2 strain, 2 species) were inhibited with addition of 20μg of pigment. The antimicrobial activitiy of the pigment on the above microorganisms was elevated by increasing a concentration of pigment in ranging from 20 to 200μg/10ml.

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Soybean fibrous protein of 0.8mm diameter was prepared by acid coagulation from dope solution. Procedure to fix the fibrous protein at its isoelectric point were examined by immersing it in salt solutions. With sodium acetate or dibasic sodium phosphate solutions of pH 4.0-6.0, it took about five minutes to increase pH of the fibrous protein to its isoelectric point under room temperature, whereas it took longer time with sodium chloride solution under the same conditions. When the fibrous protein was fixed upon heating in sodium chloride solution, solubility of protein in the solution increased with increasing heating temperature and time under conditions at 50-80°C for 2.5-10.0min. Although the solubility was low with statistical significance when the fibrous protein was fixed in sodium chloride solution at pH 4.5 or 2.5% sodium chloride solution at 50°C, it was independent of concentration of sodium chloride at pH 6.5 or 65°C. Practical procedure to fix the fibrous protein seemed to be heating at 70°C for 10min in 5% sodium chloride solution at pH 6.5.

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The aroma concentrate of a stone-milled buckwheat was prepared by SDE apparatus and analyzed by gas chromatography. Thresholds of the 16 compounds of the volatile component were determined by means of organoleptic evaluation and their odor units were calculated. On the other hand, the change in those volatile components during storage of buckwheat flour was investigated. The result of odor threshold determinations indicated that nonanal and hexanal were the most important components for the flavor of buckwheat flour. They decreased rapidly in a few days after milling.

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The characteristics were investigated with culinary sour citrus fruits yuzu (Citrus junos Sieb. ex Tanaka) and seedless yuzu (Citrus junos Tanaka [Horticultural variety: mukaku-yuzu]). (1) The fruit weight of seedless yuzu was about half of yuzu's, however, the former is seedless and its yield of juice reached to 30% being twice of the latter's. (2) The acid-sugar ratios of mature-green and mature-yellow seedless yuzu juices were 3.29 and 2.08, respectively, and those of yuzu juices were 1.20 and 2.44. (3) The pectin content in an alcohol-insoluble solid of seedless yuzu was half of yuzu's. The physical constant values of juices were similar, but the viscosity was lower in seedless yuzu. (4) There was no considerable difference between seedless yuzu and yuzu with respect to the levels of carotenoids, ascorbic acid and visible color in the juices. The organoleptic difference in the juice taste was not detected by triangle test. (5) The quantitative determination of the aroma components of peel oils revealed a similar result. The yield of peel oils of mature-yellow fruits was twice more in seedless yuzu than in yuzu.

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In order to clarify the cause for the expansion and remarkable fragility of coffee beans produced by roast, the changes of volume, specific gravity and compressive strength of the beans have been measured in the course of roast for 21min from room temperature to 240°C. The surface and the section of green, light roast, medium roast, French roast and Italian roast beans were observed by a scanning electron microscope. The volume of Italian roast beans increased about 70% more than those of green beans and specific gravity decreased from 1.16 at green ones to 0.49 at Italian roast ones. The compressive strength, which of green beans was 51.8kg, became 1.72kg at Italian roast ones. Electron microscopic observation showed that cracks on the surface of roast beans grew larger and deeper and innumerable globular microvacuoles were formed inside the beans as roast progressed. It was, therefore, ascertained that the porousness of the tissue caused by roast resulted in the expansion and the fragility of roast coffee beans.

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Low molecular weight carbohydrates in Yuba (soymilk skin) films were identified and the compositional changes in the carbohydrates during film formation were measured. Fourteen Yuba films, successively produced by a Yuba manufacturer in Kyoto, were purchased and grouped into 8 fractions in the order of film formation and the carbohydrate compositions of the fractions were determined by gas-liquid chromatography. The carbohydrate composition of Yuba films was similar to that of matured soybean seeds. Sucrose and stachyose were major sugars in the skins and followed by raffinose. Sucrose, raffinose and stachyose contents of the first and the last formed films were 1.42% and 8.03%, 0.21% and 0.53%, and 1.97% and 7.17% on dry basis, respectively. The results indicated that because of high solubility of those saccharides, they would be increasingly concentrated in the residual soymilk and their contents in films increased gradually as the film formation process proceeded.

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The alcohol fermentation of de-astringent Japanese persimmon (cv. Sanja) juice was carried out for the purpose of vineger production and changes in contents of organic acids, sugars and free amino acids during the fermentation were investigated. Most of the ethanol was produced in 3 days after inoculation of the 5% of precultured wine yeast and the ethanol concentration was finally reached to 6.2% (w/v) in 6 days. Though malic and galacturonic acids were abundant in the juice, malic acid decreased rapidly comparing with galacturonic acid during the fermentation. Glucose (5.54%) and fructose (5.03%) were the dominant sugars in the juice before the fermentation. They decreased abruptly during 2-3 days after inoculation, and glucose waS consumed more rapidly than fructose. The main free amino acids in the juice were glutamine and γ-amino-n-butyric acid. While most of free amino acids decreased during the fermentation, proline increased up to 67% of total free amino acids 6 days after the fermentation. The yellowish light orange and slightly cloudy product had light and slightly sour taste. The astringency was not perceived.

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As a part of studies on the utilization of male chicks of laying hen, chicken extract was prepared from ground chicken meat by enzymatic hydrolysis. In this experiment, one-day-old White Leghorn male chicks were slaughtered in carbon dioxide, and then ground in chopper grinder. Glycine (1%) and sodium chloride (3%) were added because the suspension of the ground chicken meat tended to spoil. The enzymatic hydrolysis of the ground chicken meat was carried out using the commercial proteolytic enzymes, Actinase AS, Bioprase SP-4, Denazyme AP and Pepsin. The chicken extract prepared by the treatment of these enzymes was not fit for seasoning since the flavor was so poor. However, the hydrolysates obtained by Actinase AS, Bioprase SP-4 and Denazyme AP were suited to prepare the media for microorganisms. Furthermore, the combined use of swine organ homogenates and Denazyme AP increased the rate of nonprotein nitrogen. Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) were well grown in the chicken extract medium supplemented with yeast extract. Gram-negative bacteria (Escherichia coli and Proteus vulgaris) showed good growth in the medium without supplements. The growth of yeast (Saccharomyces cerevisiae and Saccharomyces rouxii) was improved by adding glucose to the medium. All the tested microorganisms were practically unaffected by addtion of asparagine. These results suggest that the chicken extract could be primary source of nitrogen and secondary source of carbon as well as trace inorganic salts and water-scluble vitamins for these microorganisms.

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