Three kinds of microorganisms were used to improve flavor of commercial soy protein isolate (SPI): Saccharomyces cerevisiae, Torulopsis holmii and Aspergillus niger. The three microorganisms significantly decreased such typical beany flavors; hexanal, hexanol, and 1-octen-3-ol and increased the preferable fermented flavors; diacetyl and acetoin, which closely resemble those of fresh cheese. Protein hydrolysis occurred during ferme ntation when SPI was treated with T. holmii and A. niger. These results indicates that the fermented SPIs can be used without serious flavor problems as major protein sour ce for a wide variety of imitation dairy products.

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Chemical and biological changes in semi-dry fermented sausage, inoculated with lactic acid bacteria as starter cultures were investigated. Lactic acid bacteria, inocuated at level of 10⁷ c.f.u./g grew rapidly within 16h incubation at 37°C and kept predominant microflora in the sausage after aging for 14 days. The pH of the sausage decreased to levels of<5.0 within 16h and subsequently reached to 4.7. By the incubation at 75% relative humidity for 14 days, the water activity of the sausage decreased to O.94, which was desired value as semi-dry meat products. As the pH and water activity of the sausage decreased, the growth of coliform bacteria and staphylococci originated from meats was markedly inhibited. From the changes in free amino acid compositions and SDS-polyacrylamide gel electrophoretic patterns, it was considered that hydrolysis of meat protein occured during aging of the sausage.

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Isothiocyanates in the stems and the leaves of wasabi (W. japonica Matsum) were analyzed by gas chromatography (GC) and combined gas chromatography and mass spectrometry (GC-MS). Both of hexane and ether extracts of the stems and the leaves contained allyl, n-butyl, 3-butenyl, 4-pentenyl, 5-hexenyl, β-phenylethyl, 5-methylthiopentyl, 6-methylthiohexyl, and 7-methylthioheptyl isothiocyanates. However, the hexane and the ether extracts of stems and leaves had a characteristic greenish note like wasabi and a weak wasabi like pungent flavor, respectively. The containing ratios of 6-methylthiohexyl and 7-methylthioheptyl isothiocyanates (6-Me-NCS and 7-Me-NCS) to allyl isothiocyanate in the stems and the leaves were higher than those of roots. Then the greenish note like wasabi in the stems and the leaves seemed to be attributed to their flavor of both 6-Me-NCS and 7-Me-NCS.

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Phosphatidate phosphatase (EC 3.1.3.4) extracted from rice bran was purified 222 fold with a yield of 5.2% by ammonium sulfate precipitation and column chromatographi es on decylamin-Sepharose, DEAE-cellulose, chromatofocusing and TOYOPEARL HW-55F. The molecular weight and the isoelectric point of the enzyme were estimated to be 28 0000 and 5.3, respectively. The enzyme showed optimum pH of 5.0 and optimum temperature of 60°C. The enzyme activity increased 1.6 fold with addition 10mM Ca²⁺ and was inhibited by Ni²⁺, Mg²⁺ and PCMB. The enzyme was stable over the pH range of 3.0-8.0 and below 40°C. The Km of the enzyme for phosphatidic acid was estimated to be 1.25×10^-3M

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It is widely accepted that mixing conditions affect the gluten matrix of bread dough, though few convincing evidences have been reported. Scanning electron microscopy (SEM) is one of the most suitable methods, however, coexisting starch granules disturb the observation of gluten matrix. In this study, starch granules were partially eliminated by enzymatic degradation after fixation of gluten. Then the changes of gluten matrix during mixing process became visible. Hydrated gluten became membranous and partially covered starch granules by appropriate mixing. Excessive mixing made membranous gluten to fully envelop starch granules.

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Reversion of protoplasts to the bacillary form has been done either by plating in a soft agar layer onto the surface of hypertonic media or by spreading on the surface of hypertonic media. The spreading-plate method is constituted of two steps: all protoplasts are reversed first then fusants are detected on a minimal medium. A novel mixing-plate method, namely plating directly in hypertonic media, was proposed to make the fusion procedure much more simple than by above methods. In order to apply the mixing-plate method, protoplast reversion and fusant detection should be done by one step. Revised protoplast reversion media that could accomplish this were developed by reducing the tonicity of media less than half as customary. With those media, it was found that not only protoplast reversion could be done by the new method but also reversion frequency increased very high, perhaps because protoplasts were completely surrounded by a hypertonic reagent and a reversion stimulant as well as because the tonicity of media was reduced. It is concluded that the mixing-plate method is not only applicable but also superior to the ordinary methods.

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The production of soymilk reduced in beany flavor was investigated through a treatment process in hot water. After soaking, hulled soybeans were immersed in hot water adjusted to 70°C for 5 min before grinding. By this treatment, the content of n-hexanal in soymilk was reduced to 1% of that in untreated one and, as a result, almost no beany flavor was felt organoleptically. Further, the recovery of the solid of the soymilk was about 90% of that of the untreated one. Under the hotwater treatment conditions, among the enzymes participating in beany flavor, lipoxygenase retained its activity but hydroperoxide lyase was almost inactivated.

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Shredded cabbage was stored using ethylene acetaldehyde adsorbent (E-A adsorbent) or sucrose fatty acid esters. E-A adsorbent was prepared by treatment of activated charcoal with potassium bromate and sulfuric acid. The followings were the findings of this experiment. (1) When shredded cabbage was stored in the presence of E-A adsorbent, the concentration of ethanol, which causes the off-flavor of cabbage, was half as low as the control. This effect was attributed to the adsorption of ethanol itself rather than to the adsorption of ethylene. After 7 days storage of shredded cabbage (cultivar; Hayadori) in a O.07mm LDPE pouch, the ethanol concentration was 24ppm. In case shredded cabbage was stored with shredded carrot under the same conditions, the concentration of ethanol was 148 ppm. Therefore it is evident that shredded cabbage shouldn't be stored with shredded carrot in a same pouch. (2) Shredded cabbage was dipped into O.25% sucrose fatty acid ester and stored at 10°C. The initial bacteria number was lower than the control, but the ester had little or no bacteriostatic activity duing the storage. (3) Browning of shredded cabbage mainly depended on the oxygen concentration, so E-A adsorbent couldn't suppress the browning. The sucrose fatty acid ester suppressed the browning, but the level of ethanol was higher than that of the control.

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Effect of several a-amylase inhibitors on a-amylase activity, maximum viscosity (MV) and Falling Number (FN) of wheat flour and starch was measured to investigate the gelatinization properties of sprouted wheat flour. (1) Silver nitrate, cupper nitrate, EDTA (2K) and hydrazine sulfate showed remarkable inhibition to α-amylase activity which was measured by a simplified method developed in this experiment. (2) MV and FN of flour and starch from sprouted wheat markedly increased to the level of sound wheat when these inhibitors were applied. These results demonstrate that starch is not damaged at an early stage of sprouting and that the decrease of viscosity of flour starts when flour is processed to dough or suspension to be exposed to activated α-amylase. (3) It is possible by the utilization of EDTA or silver nitrate to measure potential MV or FN of germinated wheat without extraction of starch or elimination of protein.

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Soy milks were classified into four groups according to Japanese Agricultural Standard for soy milks; soy milk (I), prepared soy milk (II), soy milk beverage contaning fruits juice (III) and soy milk beverage containing cereal powder, etc. (IV). Prepared soy milk was divided into sub-classes; added sodium chloride as a seasoning (II-1), added vegetable oil (II-2) and added oil and tocopherols (II-3). Proximate compositions in soy milks were examined. The contents of potassium, sodium, calcium, magnesium, iron, copper, cadmium and lead were determined by atomic absorption method. The value of these elements were as follows; K: 41-243mg/100g, Na: 0.6-98.Omg/100g, Ca: 4.5-94.8mg/100g, Mg: 4.1-23.6mg/100g, Fe:0.06-0.70mg/100g, Cd: BDL (Below Detectable Level) and Pb: BDL in wet basis. The amount of linoleic acidin I, II-1, II-2, II-3, III and IV were 1.30±0.06 g/100g, 1.15±0.05g/100g, 1.83±0.20g/100g, 2.03±0.12g/100g, 0.33±0.11g/100g and 1.30±0.09 g/100g, respectively. Contents of tocopherols (α-, β-, γ-, andδ-) were determined by high performance liquid chromatography. Total tocopherols contents were found in the range 1.7-3.3mg/100g, 2.4-2.9, 3.5-4.7, 23.4-30.8, 0.5-1.2, 2.0-4.0 in I-IV, respectively.

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β-D-Galactosidase was purified from kiwifruit by ammonium sulfate fractionationfollowed by series of column chromatography on DEAE-cellulose, CM-cellulose, hydroxylapatite, Sepharose 2B, and Sephadex G-150. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 145000 by gel filtration, and the optimum pH was 3.5. The enzyme was relatively stable in the pH range of 3.5-5.0 and up to 37°C during 10min incubations. The Km values for p-nitrophenyl β-D-galactoside, lactose and lactulose were 0.6mM, 5.3mM and 6.7mM, respectively. Inhibition was observed at higher concentrations of these substrates. The effects of various compounds on the enzyme activity including metal ions, SH-reagents and sugars were investigated. The enzyme was inhibited by Hg²⁺ and 0.1mM p-chloromercuribenzoate. The other compounds had no significant effects on the activity.

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So-called crystalline taro (Suisho-imo in Japanese) occurs often in the child-corm of an early-maturing Colocasia antiquorum named cv. Ishikawa-wase. The corm looks semi-transparent at the lower part close to the binding site with the parent-corm when cutlongitudinally into halves. The tissue cells of the lower part (showing semi-transparency)were proven to be alive by causing plasmolysis in a hypertonic solution. Observations undermicroscope and naked-eye after staining with iodine-iodide solution indicated that starchgrains were not contained in the cells. According to the quantitative analyses, starch waspresent in very smaller amounts, and water in larger amounts in the lower part than in theupper part (not showing semi-transparency). The hardness of the corm was investigatedafter steaming, and the lower part was much softer than the upper part. This accorded withthe absence of starch grains in the lower part. Thus, crystalline taro proved to be inferior tohealthy taro from the viewpoint of nutrition and palatability. The method of discriminatingcrystalline taro from healthy taro without tissue destruction was devised by utilizing thedifference in specific gravity between the lower and upper parts based on the absence orpresence of starch grains. When the corms of crystalline taro were immersed in water, theyassumed the perpendicular posture, taking the lower part upwards, but those of healthy taroassumed the horizontal posture in water. The observations on taro during growing at thefields and after harvest indicated that when the leaves and stems were unsatisfactorily grown, crystalline taro often occurred.

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