Properties of mashed potatoes prepared from potatoes with high and low specific gravity were investigated. The numbers of bound cells and broken cells were greater in the low specific gravity samples than in the high specific gravity samples during a cooling off process in post-steaming. As the temperature falls in post-steaming soluble starch increased and pectin decreased, and this tendency was more remarkable for the low specific gravity samples. When the potato cells were separated with a hydrochloric acid solution (pH 1.3) and sodium hydroxide solution (pH 12.0) treatment, the cells in the high specific gravity potatoes were separated completely, but the separating ratio in the low specific gravity potatoes was about 70%. Pectin solubility by this treatment was greater in the low specific gravity potatoes than in the high specific gravity ones. The swelling temperature of the separated cells measured with photopastegraphy was 61°C for the high specific gravity potato and 66°C for the low specific gravity one.

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Lipids were extracted from six Leguminosae seeds (kidney bean, scarlet runner bean, Adzuki bean, soybean, pea, and broad bean), and the components of eight glycerolipids, four sterollipids and two sphingolipids were investigated. The yields of the total lipids in the beans, except for soybeans, were 1.6-2.7%. The major lipid classes in kidney bean, scarlet runner bean, pea and Adzuki bean were triacylglycerol (TG), phosphatidylcholine (PC) and phosphatidylethanolamine (PE), these in broad bean being PC and PE. On the other hand, in soybean TG amounted to more than 82% of the whole. Significant differences were recognized in the molecular species compositions of 1, 2-diacylglycerol moieties in glycerophospholipids among beans. However, the molecular species patterns of not only PE (APE) and PC but also of PI and PG were simillar to each other between kidney bean and scarlet runner bean, Adzuki bean and soybean, and pea and broad bean, respectively. In all beans examined, except for pea, sterol compositions of free sterols, sterylglycosides, and acylsterylglycosides showed the same pattern, but that of acylsterols was largely different. Cerebroside and ceramide were commonly detected as sphingolipid classes, the former being predominant. The constituents of cerebrosides in kidney bean, scarlet runner bean, Adzuki bean and soybean were similar, but the chemical composition of pea and broad bean cerebrosides showed notable differences, which were not recognized in the constituents of ceramides. In general, it became clear that lipids in all the beans showed structural variety, although small resemblances were recognized in some points.

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Two derivatives of 4'-galactosyllactose (4'-GL) prepared by alkali isomerization and reduction were purified. The reducing end glucose residue of 4'-GL was converted to fructose in isomerized 4'-GL (4'-GLt) and to sorbitol in reduced 4'-GL (4'-GLol), respectively. Their utilization by intestinal bacterial species were examined. 4'-GLt was utilized by bifidobacteria except Bifidobacterium bifidum, and 4'-GLol was utilized by B. adolesentis only. Bacteroides was able to utilize both 4'-GLt and 4'-GLol, but Clostridum, Eubacterium and Escherichia coli were not. As a result, the selective utilization of 4'-GLt and 4'-GLol by bifidobacteria was inferior than that of 4'-GL.

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Aroma concentrates were prepared from rice mold (kome kouji), cooked soybeans and miso at different stage of aging by a method with a porous polymer column. They were analyzed by GC and GC-MS. HEMF (4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone) contributing to the sweet aroma of miso was not identified in rice mold, cooked soybeans and miso immediately after miso mash. HEMF was identified in miso aged for 30 days after miso mash, and increased gradually with aging. Maltol and HDMF (4-hydroxy2, 5-dimethyl-3 (2H)-furanone) with sweet aroma were identified in cooked soybeans, and did not increased during aging. HEMF was considered to be made by yeast, and maltol and HDMF were considered to be generated by amino-carbonyl reaction in cooked soybeans. The aroma compounds remarkably increased with aging of miso were 4 aliphatic alcohols, 5 aromatics, 5 aliphatic ethyl esters and 3 others (methionol, 5-methyl-2-furfural and HEMF). They were considered to be responsible for the formation of miso-like aroma during aging.

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Green tea was extracted with 80% ethanol and the extract was separated with TOYO- PEARL HW-40 to obtain tea catechins, which consist of (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg). The effect of tea catechins on methyl mercaptan (CH₃SH), a main source of halitosis, was investigated in vitro. The deodorant effect of tea catechins on CH₃SH was stronger than that of sodium copper chlorophyllin, which has been widely used as an oral deodorizer. Of four main components in tea catechins, the deodorant activity increased in the following order, EC<ECg<EGC<EGCg. This implies that their activities are related to their structural formula. The inhibitory effect of tea catechins on CH₃SH production from saliva containing L-methionine was also evaluated. A large amount of CH₃SH was produced during the incubation of saliva at 37°C for 24h. But the incubation of saliva added tea catechins resulted in the remarkable depression of CH₃SH production. Tea catechins were attempted to apply to chewing gum. By chewing of gum containing tea catechins, CH₃SH production was reduced significantly. These results indicated that tea catechins showed remarkable effect on the elimination of CH₃SH, and chewing of gum containing tea catechins was useful to depress the bad breath.

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The inhibitory effects of 9 surfactants on the growth of 33 strains of yeasts belonging to 29 species of 14 genera isolated from high-sugar foods were examined. There were obvious differences in the concentration dependence of inhibitory effects of the surfactants among them. The inhibitory effects of 0.1% surfactants were likely to increase as increasing glucose concentration of culture media. The tested yeast strains were devided into 4 types based on the glucose concentration dependence of growth inhibition by 9 surfactants, but those types were not related to the groups of yeasts in taxonomy. Among the 9 surfactants, inhibitory effect of sucrose fatty acid ester S-1 and S-3 on the growth of yeasts were the highest in the presence of 1% and 20% (w/w) glucose, while that of POE (47) lauryl ether was the highest in 40% (w/w) glucose.

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To examine effects of an ethanol vapor-low oxygen combination method on the growth of yeasts isolated from high-sugar foods, inhibitory effects by an oxygen absorption typeethanol vapor generator in the range of Aw 0.97 to Aw 0.86 were compared with those by an ethanol vapor generator. Both ethanol vapor method and ethanol vapor-low oxygen combination method gave higher inhibitory effects on the growth of the tested yeast strains at lower Aw, and the combination method was more effective than the method using only ethanol vapor. The effects of the combination method were the highest against the growth of Candida tropicalis 118-40A among five tested strains. No remarkable inhibitory effects of ethanol vapor were observed in comparison with those of ethanol in media.

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Heat induced egg white gels were obtained fresh or stored shell eggs stored at 25°C by cooking in water at the increasing temperatures from 20°C to 85°C for 55min. In fresh shell eggs, the hardness of egg white gel cooked in deionized water and in 20% NaCl solution was 26×10⁴dyn/cm² and 35×10⁴dyn/cm², respectively. The hardness of heat induced egg white gel of shell eggs stored for six days was 10×10⁴dyn/cm². The creep behavior of the heat induced egg white gel was analyzed with six element mechanical models. Instantaneou elastic modules (E₀), retarded elastic modules of the first hook body (E₁), retarded elastic modules of second hook body (E₂), retarded viscous modules of the first hook body (η₁) and retarded viscous modules of the second hook body (η₂) and Newtonean viscous modules (ηn) of fresh shell egg white gels made in 20% NaCl solution were 1.06×10⁵dyn/cm², 4.16×10⁵ dyn/cm², 10.92×10⁵dyn/cm², 3.45×10⁷ poise, 12.05×10⁶ poise and 2.84×10⁸ poise, respectively. All of the scores described above were higher than those of heat induced fresh egg white gels cooked in deinonized water, All of the scores of elastic modules and viscous modules of the egg white gels of shell eggs stored for two and four days were higher than those of gels of fresh shell eggs and shell eggs stored for six days. Electromicrographs of fresh egg white gels showed the presence of small and fine structured aggregates, which were formed into spindle-shaped clusters leaving regular void spaces. Salt caused larger aggregates, which were clustered together.

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Changes in the sensory scores, chemical indices and microbial flora were examined for sardine (Sardinops melanostictus) fillets packed in an initial modified atmosphere (MA) of 20%CO2-80%N2 (v/v), 50%CO₂-50%N₂ or 70%CO₂-30%N₂ in laminated plastic bags with low gas permeability. Control samples were packed with air in plastic bags of high gas permeability. From the sensory evaluation, samples packed under MA showed nearly thrice the shelf-life of the control samples. Both aerobic and anaerobic bacterial growth were retarded depending on the enriched CO₂ concentration. When MA-stored samples were exposed to air, the bacterial counts started to increase and the rate of increase was about the same as that for the control samples. Initial microflora of fillets consisting of Vibrio (35%), Pseudomonas (17%), Moraxella, Acinetobacter, Micrococcus etc. changed to Aeromonas (70-95%) after MA storage for 14 days, while Pseudomonas (80%) and Vibrio (20%) became dominant in the control samples. Samples stored in MA for 4 days and then transferred to air were dominated by Pseudomonas (85%) and Aeromonas (10%).

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This study made it clear that specific gravity is correlative with the texture of raw potatoes and their texture changes by steaming post-treatment. Raw potatoes with high specific gravity showed high hardness, cohesiveness and gumminess. On the other hand, steamed potatoes with low specific gravity showed high hardness, cohesiveness and gumminess. As the temperature falls in steaming post-treatment, the texture of potatoes became harder and brittler. This tendency was more remarkable for the potatoes with low specific gravity.

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The changes in aroma during warm-keeping of cooked rice, either fresh harvested (fresh rice) or stored (stored rice), were analyzed by gas chromatography and subsequently characterized by principal component analysis (PCA). Volatiles on the chromatogram of both rice samples showed about 90 peaks and shoulders including 63 major peaks. Depending on the warm-keeping time, the total amount of volatile peak areas from stored rice samples were 2 to 5 times larger than those of fresh rice samples. Particularly, the hexanal peak areas of stored samples from the first 24h of warm-keeping were 4 to 7 times as large as those of fresh rice samples. Based on PCA, the distribution of principal component scores on the 1st and 2nd principal components for both rice samples suggests that their aroma profiles on PCA scattergram were markedly distinguishable between stored and fresh rice sample, and with warm-keeping time.

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Trial production of cheese analogs from soybeans by using limited proteolysis was attempted. Ground whole soybeans and soymilk were coagulated by treatment with bromelain followed by rapid heating with a microwave oven. The materials were treated with the enzyme at low temperature (5°C-room temperature) to bring about limited proteolysis of soybean protein. Slow heating caused over-digestion and loss of coagulation ability of soybean protein because of delayed inactivation of the protease. Cheese analogs similar to processed cheese were obtained in the both procedures. Hardened oil and sodium caseinate were used as common ingredients. Soybeans were ground and emulsified with other ingredient followed by the enzyme addition, therefore, no waste like "Okara" was exhausted from this process. About 25% of whole protein was soybean protein. Soymilkcurd was also obtained from soymilk by the enzyme treatment and the microwave heating. Emulsification of the curd with some ingredients gave cheese analogs having good texture. Soybean protein formed 55-76% of the whole protein in these analogs.

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