Surface-modified glass microfiltration membranes treated with two types of silane coupling agents (γ-APS, PFS) were applied to cross-flow filtration of beer, in order to prevent the membrane fouling. The effect of surface-modification of membrane on the permeating flux was examined, and the following results were obtained. The γ-APS-treated membrane and the PFS-treated membrane caused zeta-potential of membranes in beer, plus and minus, respectively, compared to the untreated membrane. But the blocking of membrane pore was assumed in PFS treatment. At the feed velocity of 0.5ms^-1, the steady-state flux was constant, not affected by the membrane potential, on the other hand, at the feed velocity of 2.5ms^-1, the steady-state flux increased with a decrease of the membrane potential. As the PFS-treated membrane was able to prevent the membrane fouling by yeast at the feed velocity of 2.5ms^-1, the cake layer resistance of PFS-treated membrane was approximately 16% of that of the untreated membrane. As the result, the steady-state flux was about twice as much as that of the unteated membrane.

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To investigate the difference in palate between Korean and Japanese people, we analyzed oligopeptides, free amino acids, 5'-ribonucleotides and free sugars of salted preserves from Korea and Japan. The salted preserves from Korea were grouped into 3 classes, "Food Market (Korea)", Side Dish (Korea)", "Bottled (Korea)". The "Side Dish (Korea)"and the "Bottled (Korea)"types are made by adding seasonings, red pepper or other food materials to the "Food Market (Korea)". The salted preserves from Japan were bottled goods purchased at food stores, and they were classified as "Bottled (Japan)". The results were as follws: (1) Sodium chloride was 23.2% in the "Food Market (Korea)" type, 14.4% in the "Side Dish (Korea)", 7.1% in the "Bottled (Korea)"and 5.8% in the "Bottled (Japan)", respectively. (2) The"Food Market (Korea)" didn't contain free sugars, but all the other salted preserves contained 3500-6500mg free sugars/100g. (3) None of the salted preserves contained 5'-IMP or 5'-GMP. (4) The main free amino acids of the "Side Dish (Korea)" were glutamic acid, leucine and alanine, but the "Bottled (Japan)"contained an extremely high amount of glutamic acid. (5) The oligopeptide content in the"Side Dish (Korea)"was nearly 4 times more than the"Bottled (Japan)", but the major amino acid compositions of the oligopeptides were almost same, and glutamic acid was a main constituent of them.

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A method of selecting the inventories and TV commercial films (CFs) for measuring consumers' response to CFs of foods was studied. The audio-vidual experiment was done using 131 CFs. The elements of composition of each CF were evaluated in 20 inventories by the authors. The elements of psychological evaluation of each CF were evaluated in 47 inventories by 28 panelists. A factor analysis was carried out to refine these inventories and a cluster analysis was carried out using the factor scores of each CF to select CFs. The results were as follows: (1) The inventories were rationally reduced 31 ones. (2) 131 CFs were classified into 9 clusters. More than one CFs should be selected from each cluster for measuring consumers' response to CFs of foods.

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A cross-flow filtration method with backpressure washing by nitrogen gas was applied to fermented beer by using 2 glass membranes with different pore sizes, 0.23μm and 0.72/μm, in order to prevent membrane fouling. The effect of backpressure washing conditionon filtration flux was examined, and the following results were obtained. Average filtration flux could increase by backpressure washing. Optimum backpressure washing in terval was every three minutes. The cake layer resistance formed on membrane surface could decrease by backpressure washing, but the plugging resistance formed in membrane pore could not decrease. Optimum backpressure washing pressure was 100kPa, and the pressure more than 100kPa let average flux decrease. The effectiveness of backpressure washing was dependent on the pore size of filtration membrane. Backpressure washing of 0.23μm membrane was more effective than that of 0.72μm membrane. The backpressure washing in a surface plugging state of membrane was more effective than that in an inner plugging state.

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The method using the calboxylic acid analyzer was developed for determination of N-acetylneuraminic acid (NANA) in food. Before injection into a calboxylic acid analyzer, 9ml of sample solution (one gram of powderd sample was suspended and diluted in 50ml of water) was hydrolyzed with 1ml of 1N H₂SO₄ at 80°C for 45min and filtrated with membrane-filter (pore size; 0.45μm). A hundredμl of the filtrate was injected into a calboxylic acid analyzer. The calboxylic acid analyzer had a basic anion exchanger column and 0.2N HCl was used as a mobile phase, and a spectrophotometer was equipped for measuring the absorbance at 530nm. NANA was activated by reacting with 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride and reacted with 2-nitrophenyl hydrazine continuously, followed by coloring to red (530nm) by heating in strongly alkaline solution. The detection limit of this method was 10μg of NANA in 1g of the sample. The coefficients of variation was 2.7% (n=10). This method could be applied to determination of NANA in various foods.

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Aroma concentrates were prepared by absorbing aroma compounds to porous polymer and eluting them with ether from 48 kinds of rice miso which were exhibited at the 32nd National Miso Competition. Aroma concentrates were analyzed by gas chromatography (GC) and GC-mass spectrometry (MS), and concentrations of the selected 92 peaks were used as variables for statistical analyses. These rice miso were evaluated and classified to three classes by sensory test. The compound having the highest correlation coefficient between the variables and sensory scores was HEMF (4-hydroxy-2 (or 5)-ethyl-5 (or2)-methyl 3 (2H)-furanone). By the stepwise discriminant analysis of 46 major peaks, HEMF was also selected by step l and evaluated as the most contributing compound. From these results, HEMF was considered to contribute remarkably to sensory evaluation and classification. Fourteen peaks were selected by the stepwise discriminant analysis. The 14 peaks variables were able to explain on 76% of the total variation. Using the 14 peaks variables, all rice miso were classified correctly into three classes by canonical discriminant analysis.

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Prevention of tartar or argol precipitation in single strength juice of Concord grape (Vitis labrusca L.), that is tartar stabilization, was investigated by means of ion-exchange resins in batch system. Addition of weak basic anion resins, either Diaion WA 10 or Diaion WA 30 resulted in lowering of the titratable acidity. The decrease of acidity was nearly reached to a steady state for 30min after addition of resins. The acidity and tartaric acid in the grape juice treated by 3% (w/v) of weak basic anion resins decreased to 63% and 70%, respectively. On the other hand, potassium content dropped using strong acidic cation resins, either Diaion SK 1 B or Diaion SK 116. The potassium of the grape juice treated by SK 116 decreased to 30% or below, compared with initial potassium content. The tartar precipitation was not observed in the Concord grape juice treated by the weak basic anion resin followed by the strong acidic cation resin. However, the ratio of decrease of soluble solids and amino-form nitrogen was 10 and 30%, respectively. Anthocyanin content in the grape juice treated by both the weak basic and the strong acidic resins was only half of initial content due to adsorption by the resins. From these results, advantage of ion exchange resins was discussed to save labor power and shorten consuming-time in the tartar removal process during the manufacture of grape juice.

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The effects of various environmental conditions, including exposure to light and fruit load, on the contents of sugars and ascorbic acid in'Senshu' apple fruit, which is suitable to a high quality juice, were investigated.
(1) The contents of glucose, fructose and sucrose decreased by shading and bagging. The content of sucrose was greatly reduced by shading. The content of ascorbic acid was also reduced by bagging and shading. (2) Defoliation treatment reduced the total sugar content, especially sucrose. The ascorbic acid content was also reduced. Overcropping treatment reduced the fructose and sucrose contents greatly, and the ascorbic acid content was also reduced. However, the levels of the sugars and acid in better coloring fruits were higher than that of lower coloring. It was suggested that among the sugars sucrose was especially affected by the light conditions and fruit cropping, while ascorbic acid was related to photosynthate in addition to exposure to light.

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Transfer rate of saccharose in tuna flesh was measured as a part of studies on mass transfer of several kind of substances in fish flesh. As a result, it was expressed isotropically by diffusion mechanism like as those on glucose and salts reported in our previous papers. The relationships between diffusivities in fish flesh and in water were approximated by two straight lines, for salts of uni-valent cations and bi-valent cations, on a log-log plot. Glucose and saccharose were correlated closely to the latter line. From these results, equations expressing the relation between apparent diffusivities in fish flesh and in water were proposed.

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Changes in physical properties of cooked noodle and chemical compositions of Japanese type noodle during drying were investigated. Acetic acid soluble protein showed a minimum value at 5hs from start, and increased slightly with drying. The decrease of acetic acid soluble protein was considered to be caused by mainly insolubilizing of glutenin. However, non protein nitrogen increased with drying. While both the free lipid and the lipid extracted with chlorofolm-methanol (2:1) from noodle decreased, the hot chlorofolm-methanol extractable lipid increased markedly during drying. The result suggested that strength of lipid bonding to noodle was strengthen by drying. Cutting strength, tensile strength and extensibility of the cooked noodle decreased with drying. These results suggested that the changes in both protein and lipid of the noodle participated with the changes in physical properties of the cooked noodle by drying.

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To make clear the effect of ashed egg shell on the hardness of brined ume fruit (Prunes mume Sieb. et Zucc), ume fruit was brined with either regular salt (S¹), or a specialized salt solution (S²), after an addition of lime (Calcium hydroxide) or ashed egg shell. After that, 1% S¹ or S² was added against the brined ume fruit once a day until their content in the fruit reached to 15% concentration. Six months after the final addition of S¹ or or S², the hardness and content of Ca and Mg in the brined ume fruit were measured with a rheometer and high performance liquid chromatography, respectively. The pectin content was also determined in the same relative samples. The results obtained were as follows: (1) The texture of the ume fruit softend with brining, but that brined with S² was a little harder than that brined in S¹. In addition, the lime or ashed egg shell suppressed the decrease of the hardness of the fruit brined with either S¹ or S²; (2) Ca content of the fruit increased with the addition of lime or asked egg shell; (3) During the brining, the HSP (HCI soluble pectin) increased and WSP (Water soluble pectin) and HXSP (Hexametaphosphate soluble pectin) contents were decreased. But in the case of fruit brined with S¹, WSP decreased and HSP and HXSP increased with the addition of lime or ashed egg shell. On the other hand, in the case of brining with S², WSP decreased and HSP increased. As a result of these experiments, it was presumed that the increased amount of Ca ions in the tissue might form much more additional cross-linkage within the pectin molecules during brining with lime or ashed egg shell, which follows the decrease of WSP and increase of HSP or HXSP that was maintained by the hardness of texture.

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To make use of the yeast killer toxin, we attempted to screen Kluyveromyces strains producing a killer toxin which acts in the presence of NaCl. Among Kluyveromyces IFO type strains tested, K. thermotolerans IFO 1778, K. vanudenii IFO 1673, K. lactis IFO 1267 and K. phafii IFO 1672 strains were shown to have killer activities against Z. rouxii in the presence of NaCl. And K. thermotolerans IFO 1778 strain showed the most marked effect on the growth of Z. rouxii in the presence of NaCl. The killer type of IFO 1778 strain did not correspond to the K₁-K₁₁ type, and its killer character seemed to be controlled by nuclear gene(s).

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We sometimes feel harder or softer parts when we eat the steamed corms of taro, Colocasia esculenta. We found that the texture after steaming of child-corms of so-called crystalline taro, often occurring in cv. Ishikawa-wase, was harder or softer in the crystalline part (the lower part close to the binding site with the parent-corm) than in the non-crystalline part (the upper part close to the grandchild-corm). We recognized that the hardest portion in the texture was localized in the central part including the boundary line between the above two parts. Next, we investigated the texture in the steamed corms of so-called "washed tar" (Arai-satoimo in Japanese), peeled and water-immersed taro. The outer part, 1-2mm thick inward from the peeled-outer surface, was harder in texture than the inner part. In reference to the inhomogeneity of the texture in the above two kinds of corms, the corms were peeled and divided into two groups. One was left on wet paper in a box for 3d, and the other was immersed in water for 7d. The texture in the two after steaming was then investigated. It was harder in the outer part than in the inner part, in both cases. The hardness in all of the above experiments was investigated qualitatively by metal spitsticking and mouthfeel and quantitatively by the measurement of the textural values such as hardness, consistency and breaking strength with a curdmeter.

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Water-soluble hemicellulose (WSH) extracted from wheat bran by homogenizing with dilute (0.2M) NaOH solution was purified by ultrafiltration and ion-exchange resins. The yield of the final product (WSH) was 7.6% of the bran. The molecular weight distribution of WSH, which was determined by gel filtration chromatography on size-exclusion HPLC, showed that the WSH consisted of polysaccharides of wide molecular weight distribution with a peak of around 350000 dalton. The analysis of sugar composition. showed that the WSH was a highly substituted arabinoxylan in which the ratio of arabinose to xylose was 0.91. The viscosity of the aqueous WSH solution was exponentially correlative to the WSH concentration. WSH was unstable on the condition of low pH (pH 3 and 5) and high temperature (80-100°C), but it was stable at higher pH (pH 9), even at high temperature (80-100°C). It was also shown that WSH had a unique characteristic, a sustained release function, which had never been demonstrated in other polysaccharides such as starch and cellulose. By this function, the tablet comprising bromphenol blue with in a matrix of WSH could gradually release this substance into the solution as the tablet was being dissolved in the aqueous phase. The effect was observed even with a tablet of a mixture containing only 20% WSH with 80% cellulose.

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Expansion of yeasted dough in a glass cylinder with time was followed by measuring the dough height with a cathetometer. The gassing power of the dough was estimated by collecting the expelled air and the released carbon dioxide. The volume of dough at which CO₂ began to escape from the dough, estimated from the gassing power and dough expansion curves, was higher for rapidly-expanding and oxidized doughs than for slowly-expanding, reduced and control doughs.The doughs which showed higher volumes at the point of CO₂ leakage had higher tension of the surface membrane. The top surface of yeasted doughs in the glass cylinder, determined from the measured volume of the dough meniscus, appeared to have the shape of a revolving parabola rather than that of a revolving ellipsoid. In the comparison of these results obtained from the behavior of the dough surface membrane with the results of test baking the former data were found to be applicable to the basic research on baking properties of dough.

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