Competitive adsorption on air/water surface was investigated in a sodium caseinate/surfactant system. Surface tension data on caseinate/surfactant mixtures gave information on their interactions. The values of surface tension were measured for soy lysophosphatidylcholine (SLPC), SLPC/fatty acid (FA) mixtures, soy lysophospholipid (SLP), sucrose mono-distearate (SE) and SLP/SE mixture as a function of surfactant concentration in the presence or absence of caseinate. SE and SLPC which is neutral lipid had no interaction with the protein. On the other hand, SLP and equimolar mixtures of SLPC/FA interacted strongly with the protein, both at the interface and in bulk solution, and it was suggested that electrostatic complex formation might have occurred. SLP was added to SE for the preparation of O/W emulsions containing caseinate. The addition of SLP improved quality and stability of the emulsions. It seems that the protein/SLP complex molecules attach tightly to the droplets and stabilize the emulsions, whereas the stability of emulsion prepared with the same amount of LPC was poor. Therefore, it is suggested that the protein moleculs are displaced from the droplet surface by the action of excessive surfactant.

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A gas chromatographic system equipped with a thermal conductivity detector (TCD) was developed for simultaneous determination of inorganic gases including nitrogen, oxygen, carbon dioxide and argon in flexible pouches. The four gases were separated by a capillary column system of Molsieve 5A PLOT and PoraPLOT Q linked in parallel. The split ratio of the gas flow at a diverging point of the linked column was controlled by adding fused silica capillary tubes in series. When the relative response of TCD to each gas was considered, the atmospheric gas composition analysis by this system proved this system to be highly acceptable. Linearity of calibration curves suggested possible determination of 0.1% oxygen and 0.02% carbon dioxide. Low oxygen levels in a modified atmosphere packaging of pimientos and in packaging with oxygen absorber were accurately monitored during storage. The gas chromatographic procedure developed can be applicable to design for modified atmosphere packaging and oxygen absorber packaging for the optimization of these packaging systems.

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The saccharides extracted from rice grains with and without monoglyceride into aqueous layer during cooking process was investigated. Monoglyceride (0.5% of the rice) was added when the temperature of an electric rice cooker reached to 80°C. The aqueous layer was separated from rice by sieve at 0min., 5min. and 10min. after the starting period. The aqueous layer was further separated to two fractions, supernatant and residue, by centrifugation (12000rpm). After 10min. aqueous layer could not be separated, because it was perfectly absorbed into rice grains. The results were as following; 1) Amounts of saccharides in both fractions increased during cooking until 10min. 2) The supernatant of 0min. contained sucrose and glycerol except glucosides. Glucose and maltos increased until 5min. Amylose and dextrin increased until 10min.. 3) The residue contained amylose and partially hydrolyzed amylopectin, and amounts of the both components increased until 10min.. 4) Monoglyceride decreased amylose content in the residue of 10min., but pretreatment of the residue with DMSO revealed that little difference exist in amylose content between the both residue with and without monoglyceride. This observation suggested formation of amylose-monoglyceride complex in the residue. This complex should be absorbed again in the surface area of rice during cooking, hence the complex would significantly affect to physical properties of cooked rice.

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Ethyl-α-glucoside (α-EG) is a tasty component of sake and mirin. To establish an enzymatic mass-producing method of α-EG, an ability to synthesize α-EG was examined among some commer- cial amylases and related enzymes. Transglucosidase L [Amano] from Aspergillus sp. was selected, and α-EG synthesis by a purified α-glucosidase from the α-glucosidase preparation was confirmed by high performance liquid chromatography, IR, and 13C-NMR. For mass-production of α-EG using Transglucosidase L [Amano], the reaction conditions were as follows: substrate, Oligotose (liquid); substrate conc., 10% (w/v); ethanol conc., 60% (v/v); temperature, 45°C; enzyme conc., 6.6units/g substrate; reaction time, 24h; pH, 6.0 (deionized water); shaking, 200rpm. Under these conditions, transglucosylation dominated over hydrolysis of substrate and α-EG was synthesized efficiently. α-EG was manufactured by means of enzyme inactivation, filtration, distillation, decolorization, deionization, and concentration procedures in order. α-EG syrup thus obtained contained 51.3% sugar (α-EG, 25.1%; glucose, 23.7%; others 2.5%). Mutagenicity and acute toxicity of α-EG were negative. α-EG addition was effective in deodorizing bad smell from fish and animal meats, softening salty taste, and improving all-round taste for food cooking.

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Possibility of near infrared (NIR) spectroscopy for analysis of changes in structure of starch due to gelatinization, and deteryination of degree of gelatinization was investigated. Among second derivative NIR specsra of rice starch samples having different degrees of gelatinization, largedeviations of spectra were observed at 1204, 1368, 1436, 1700, 1748, 1784, 1924, 2088, 2280, 2320 and 2348nm. Especially, specsra in the vicinity of 2100 and 2280nm changed complexly according to progress of gelatinizasion. As a result of linear regression using second derivative a bsorbance values of NIR specsra and degrees of gelatinizasion by BAP method, high correlations were obtained in the vicinity of 1807nm and 2095nm. In the vicinisy of l807nm, characseristic absorpsion band due to starch was notobserved. The parsicle size could be one of reasons why high correlation was obtained, because high correlation existed besween degree of gelatinization and particle size. In the vicinity of 2100nm, absorpsion due to starch and diffusion due to particle size overlapped. Then principal component (PC) analysis was applied to NIR spectra from 2040nm to 2144nm to reduce the effect of the diffusion on NIR spectra. Accurate linearity was obtained between second PC score and degree of gelatinization by BAP method. It was concluded that NIR specsroscopy has possibility to determine degree of gelatinization.

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Laying hens were fed vitamin D₂-fortified shiitake (vitamin D₂ content 5000IU/g) diet on 0.1- 0.4% addition levels for 28 days. Transfer of vitamin D₂ in shiitake to egg yolk was confirmed by HPLC analysis. The vitamin D content (total amount of D₂ and D₃) in egg yolk increased steeply to the 7th day. After that it increased gradually until the 28 th day. The vitamin D content in egg yolk was 14.5IU/g on 0.4% addition at the 28 th day and was about 10-times that of control eggs, then the transfer ratio of vitamin D was 8.9%. The vitamin D content in egg yolk increased in proportion to the addition amount of fortified shiitake, therefore it may be possible to produce eggs of any vitamin D content. Vitamin D-fortified shiitake had no influence on performance of laying hens, eggshell quality and plasma calcium and phosphorus concentrations of laying hens.

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Kamaboko containing a lot of voids which arise from the air bubbles taken in the grinding process of fish meat during manufacturing is complained about its poor quality. An ultrasonic pulse echo technique was applied to evaluate the size and number of these voids in kamaboko by using a standard ultrasonic inspection apparatus (a single-type). The frequency used was 2.25MHz. The number of voids larger than 1mm diameter in kamaboko was determined by counting the number of ultrasonic echo pulses on the oscillograms. The number of echo pulses gradually increased as the increase of the number of voids while the voids' number was small. However, an abrupt saturation of detecting echo pulse took place. This may be caused by a rapid growth of the shaded space generated by void particles which reflected ultrasonic pulse wave. This phenomena was simulated by a simplified model calculation, which suggested a way of avoiding saturation. The non-destructive detection of voids in kamaboko using ultrasonic technique is concluded to feasible.

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The contents of proximate components, low molecular weight carbohydrates, organic acids, free amino acids and 5'-nucleotides in fruit-bodies of Lyophyllum shimeji (Honshimeji Mushroom) grown on artificial bed-blocks were examined. The crude protein content was 30.4% and the carbohydrate was 57.7% in dry weight. The low molecular weight carbohydrate content was 14.6% in dry weight. In low molecular weight carbohydrates component, trehalose was the dominant and was 12.0% in dry weight. The organic acid content was 3.81% in dry weight. In organic acids component, malic, citric, fumaric and succinic acids were the dominant. The total free amino acid content was 2.88% in dry weight. In free amino acids component, glutamine, ornithine, arginine, alanine, glutamic acid and glycine were the dominant. The 5'-GMP content was 0.31% in dry weight.

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Possibility of nondestructive determination of sugar content, acidity and hardness in 'Ooishi Wase' plum fruit by near infrared (NIR) spectroscopy was examined. Calibrations were constructed by stepwise multiple linear regression analysis using NIR absorbance value and sugar content, acidity or hardness. As a result, correlation coefficients between chemically analyzed data and NIR were 0.92 for brix, 0.78 for acidity and 0.83 for hardness, and standard errors of estimation were 0.41°Brix, 0.11% and 0.21kg, respectively. Standard errors of prediction were 0.61°Brix for brix, 0.19% for acidity and 0.21kg for hardness, suggesting that the NIR spectroscopy has possibility to determine sugar content and hardness except acidity in plum fruit. There is currently great interest in measurement of hardness of fruit by NIR spectroscopy.

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In order to produce vinegar with super high acidity (acetic acid concentration more than 20w/v%), cultivation conditions with Acetobacter polyoxogenes, which has been adopted for production of vinegar with high acidity (acetic acid 15w/v%), was improved. It was concluded that a fed batch culture method was favourable to raise the final acidity of vinegar. However, high acetic acid concentration considerably inhibited the growth of the bacteria and their acetic acid productivity. It was supposed that a theoretical final acidity might reach 23w/v%, if the extent of inhibition by acetic acid was kept as that of 15w/v% acidity. In practice, wes ucceeded to produce the vinegar with super high acidity (21.75w/v%) by the programmed temperature cultivation method, comprised of two stages. In the first stage, incubation temperature was kept at 28-29°Cuntil acidity reached 12w/v% level, then, in the second stage, the temperature was let down gradually to 15°Cwith higher acidity.

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Jinhua Huotui is a traditional fermented food in China, and has been made for more than 800 years. Jinhua Houtui is produced by fermenting ham (liang tou wu zhu) with some microoganisms for about 5 months, and is used for a stock of special Chinese food. General components of Jinhua Huotui are as follow; water contents was 23.9%, crude protein and crude lipid were 23.7% and 44.3%, respectively. There were no difference in the total amino acid content between Jinhua Huotui and ham in the market. But the content of free amino acids of Jinhua Houtui was higher than that of ham, especially glutamic acid was rich (464 mg/100g). Jinhua Huotui also contained high amount of 5'-inosinic acid (447ppm). Each mycotoxin (Aflatoxin G₁, G₂, B₁, B₂; Ochratoxin A; Patulin; Zearalenone) was not detected and, so that Jinhua Huotui was a safety stock about mycotoxins and heavy metals for Chinese food. Mold counts were about 10⁴-10⁶ cfu/g, bacteria counts were about 10³-10⁵ cfu/g, and yeast counts were 10³-10⁵ cfu/g. The majority of microorganism were mold.

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To presume maximum viscosity (MV) obtained by amylography a method based on alpha- amylase activity was developed. Alpha-amylase activity was assayed using blocked p-nitro- phenylmaltoheptaoside as a substrate (CERALPHA METHOD, Megazyme Pty. Ltd., Australia). MV and alpha-amylase activity were determined in various flours prepared by mixing flours obtained from germinated and ungerminated wheats at various ratios. Loge MV decreased linearly with increasing of loge alpha-amylase activity. Regression lines of 4 varieties and one brand of wheat flours were different from each other, but the differences were very small in the low MV region which corresponds to wheat sprouted to some extent. Therefore, we made a tentative criterion to presume MV, that is, sprout damaged wheat, by alpha-amylase activity. Group 1: Wheat with alpha-amylase activity below 70mU/g flour; wheat must be undamaged. Group 2: Wheat with alpha-amylase activity 70mU to 100mU/g flour; wheat may be sprout damaged. Group 3: Wheat with alpha-amylase activity above 100mU/g flour; wheat must be sprout damaged. In order to examine adaptation of the criterion, 29 wheat samples which sprouted or unsprouted in fields were analyzed. The result indicated that the criterion may be available to judge sprouted wheats. With CERALPHA METHOD, almost 60 samples are analyzed in a day. Therefore sprout damaged wheats can be classified rapidly compared with amylography method.

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We derived a general expression for the time and temperature dependence of both the hardening and the softening rates of vegetables during cooking on the basis of rate laws. The vegetables studied were such root vegetables as Japanese radish, carrot, burdock and potato. Our kinetic model was based on the following two assumptions: (1) Pectin is transformed into three forms, i.e., the unchanged pectin, the hardening pectin and the softening pectin. (2) Each pectin contributes additively to the hardness of the vegetables. Considering the causes of the hardening and the softening as enzymatic deesterification and β-elimination, respectively, first-order rate laws were applied to the formation of each pectin and to the inactivation of the enzyme. Rate constants for relevant processes were determined at different temperatures by fitting integrated rate equations to the cooking data by the least-squares method. The hardness calculated from the derived expression was in good agreement with the experimental values for all samples. Using the kinetic parameters determined here, we could reproduce not only the simultaneous occurrence of the hardening and softening processes but also the desired cooking time for optimum hardness. The hardening rate constant showed Arrhenius behavior between 54 and 63°C, but a non-Arrhenius one at higher temperatures. It was suggested that the hardening process was complex in the high temperature region of 70-99.5°C.

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