Potato samples (7mm diam.×30mm length) were cooked in water with a cylindrical heating vessel in a temperature range from 85 to 105°C. Changes in hardness of the potato samples during cooking processes were measured for calculating the softening rate constant. Since the cooking processes consisted from the non-isothermal heating and cooling periods and the isothermal cooking period, the softening rate constants evaluated from the to toal time of the cooking processes meant merely the apparent rate constants for each cooking temperature. Thus the cooking time was corrected for evaluating the real softening rate parameters for the quoted temperature by estimating the progress of the softening of potato during the non-isothermal periods on the basis of a numerical integration method of softening rate. Relationships between the cooking curve of potato and the corrected cooking time showed good adaptation to a lst order rate equation. The activation energy was estimated to be 160kJ/mol, which was larger than 113kJ/mol being calculated from the apparent rate constants.

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Suitability of Quantification-I analysis was examined to predict noodle eating quality from physicochemical factors of 60% extraction flour from Japanese domestic wheat and to evaluate quantitative effect of the factors on the extent of noodle eating quality.
1. The following physicochemical properties among major items were obtained as dominant factors which improve or deteriorate the noodle eating quality
(1) Preferable factors: color grader value, below O.99; protein content, above 8.3%; variety rank, I; Breakdown, below 209; amylose content, below 24.9%.
When these requirements are met coincidentally in a sample, its noodle eating quality score by sensory test is expected to be improved by 9 points.
(2) Uedesirable factors: color grader value, above 1.80; amylose content, above 26.5%; variety rank, III & IV; protein content, below 7.0%.
2. A high correlation was observed between the observed and the predicted values from the calculation by Quantification-I with color grader value, amylose and protein contents, breakdown and variety rank: r=0.797^***, SEC=1.485 (n=41). The result confirmed that Quantification-I analysis is suitable for predicting the noodle eating quality from the physicochemical factors of wheat flour.

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The tendency of light scattering at milk coagulation was investigated by means of optical fiber for process control of cheese or yoghurt processing. Ingredient or measuring direction of light scattering or wave length was varied and also an optical fiber with modified tip was employed. The tips of both optical fibers from the light source and the sensor were immersed in mixed ingredient solution and light scattering were measured continuously. Raw output signal and first derivative of output signal from the amplifier for the sensor were recorded. In all processes tested under different conditions of cheese processing, the beginning of coagulation was observed at the location immediately after the first obvious peak on the first derivative curve. Similar results were also obtained in the case of yoghurt. The tendencies of light scattering were correlated to those of curd-tension measured simultaneously in cheese processing. Some experiments, in which concentration of rennet or concentration of calcium chloride or heat treatment of raw milk were varied, were carried out. Two obvious peaks were observed on most of first derivative curves. To make heavier the heat treatment of raw milk caused the height of the first peak lower and the second peak later. When the amount of rennet and/or calcium chloride were increased, the appearances of both of the first and the second peaks became faster and the height of the first peak was increased. The relations between the curd-tension values obtained after 60minutes and the height of first peak or the appearance time of second peak were such that the higher the first peak became or the shorter the appearance time of the second peak became, the higher the curd-tension value tended to. The tendencies of light scattering depended on measured angle, but the locations of the peak on the first derivative curve coincided with each other. In the measurement of light scattering at the direction of 180°, when the tip of the double track optical fiber from the sensor and the light source was covered with plane glass plate, polarity of second peak reversed, and the whole shape of the light scattering curve showed reverse shape of the measuring curve at O° with respect to abscissa. These observations are supposed to mean rapid shrinking of the clot at the second peak. No fundamental difference was observed in the results of light scattering pattern at the direction of 180°, with red light (660nm) and green light (565nm) in the cheese and also yoghurt processing. These results suggest that the size of casein micelle does not increase at coagulation. Light scattering measurement seemed to propose the possibility for monitering of milk coagulation and for the prediction of the properties of finished curd.

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Heat-treated coagulation of water soluble soybean proteins pre-treated with stem bromelain was investigated by determination of sulfhydryl content and hydrophobicity, by polyacrylamide gel electrophoresis and by scanning electron microscopy. Textures of curd prepared by heat-treatment of soybean milk pre-treated with bromelain were compared with those of calcium and lactic fermentation curds. Approximately 60% of total nitrogen was recovered in the heat-treated coagulate of water soluble protein pre-treated with bromelain. Sulfhydryl contents and hydrophobicities were gradually reduced with bromelain treatment and further reduction of them was shown after the heat treatment. The subunits of 7S globulin were converted to lower molecular fragments with the enzyme treatment, although the subunits of llS globulin were limited to partial hydrolysis and retained in coagulate. Scanning electron microscopy revealed a structure composed of aggregates with small particles. Curd from the heat-treated soybean milk pre-treated with bromelain had lower shear-stress, hardness, cohesiveness, springiness, and chewiness.

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Inhibitory mechanism of allylisothiocyanate (AITC) on browing of shredded cabbageduring storage was investigated. Browing of shredded cabbage treated with AITC (>2.5mg/100g) was suppressed, while control sample treated with distilled water turned to brown. Activity of polyphenol oxidase (PPO) and the content of total phenols increased during storage, but such changes were not observed in the case of shredded cabbage treated with AITC. Activity of phenylalanine ammonia-lyase (PAL) increased markedly during storage, on which AITC also indicated inhibitory effect. Direct inhibition of AITC on the activity of PPO and PAL was not observed at the level of concentration that could inhibit browing almost perfectly, if treated immediately after cutting. From these results, it was suggested that the inhibitory mechanism of AITC on browing of shredded cabbage during storage was due to the inhibition by AITC on the increase in PAL and PPO activity, which was induced by wounding.

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The thermal conversion of creatine (CR) to creatinine (CRN) in a phosphate buffer solution (pH6.5) at temperature ranging from 100 to 145°C was studied from a kinetic viewpoint. The heating process consisted of unsteady heating and cooling periods, and constant temperature heating periods. Since the conversion of CR to CRN progressed during the unsteady thermal process, heating time for it was corrected to the value of heating time under the constant temperature. When 60-76% of the CR converted to CRN, the conversion reached to an equilibrium. Therefore, the conversion of CR to CRN was regarded as a reversible reaction. The thermal conversion curve of CR to CRN calculated from a reversible lst order rate equation was best fitted into the measured conversion curve. The rate constants and activation energy for the forward reaction (CR→CRN) were estimated as 1.1-33.1x10^-4·s^-1 and 97.9 kJ·mol^-1, respectively. These kinetic parameters for the reverse reaction (CRN→CR) were estimated as 0.7-10.3×10^-4·s^-1 and 79.4kJ·mol^-1, respectively. Consequently the heat of reaction for this reversible reaction was estimated as 18.5kJ·mol^-1.

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The vapor pressure of a series of edible oils (soybean oil, rape seed oil, cotton-seed oil, safflower oil, rice wax and sesami oil) were measured in a range of 250 to 330°C using an assembly of U-tube mercury manometer and vacuum pump. The application of the Riedel's type equation to the results was tried to obtain relationship between the vapor pressure and the temperature. The results obtaind could be summarized, as follows: (1) The vapor pressure increased with increasing temperature. For soybean oil, rape seed oil, cotton-seed oil and rice wax they showed sigmoid curves which had a inflection point at about 290°C. As to sesami oil the curve had the constant value in a range from 280 to 300°C. Only in safflower oil the curve showed simple exponential type. (2) Generally, vapor pressure was estimated from the integral of the Clausius-Clapeyron's equation assuming constant evaporation heat. Such equation could not express on these simoid type curves. Thus the Riedel's type equation with 4 parameters was introduced. As the results, the data of each oil could be ftted to the equation by the leasts squares method as follows: ln Pvp=A+B·T^-1+C·ln T+D·T⁶ The results agreed well with the experimental results whoce standard deviations were in the range of 0.3026-0.9043kPa. The latent heat of evaporakion could be estimated from the Eqation.

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In the previous paper, we reported that using carbon dioxide alone as an extractant, limonene could be extracted with high selectivity only when the solubility in the supercritical fluid less than 1.1%. In this paper, the effects of ethanol as an entrainer were discussed for preperation of terpeneless oil. The experimental conditions were as follows: extraction pressure; 75-120atm, extraction temperature; 40-600°C, ratio of ethanol to carbon dioxide; 1.4-12%. The effects of the entrainer were more significant at lower extraction temperatures. The ektract rich in oxygen-containing terpenes by 1.7-2.3 times than the original sample was obtained under following conditions: extraction pressure; 100atm, extraction temperature; 40°C, ethanol ratio; 3.1%. Then, the solubility in the supercritical fluid was 6.6%.

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The preservative effect of ε-poly-lysine (PL) was investigated under different PL concentrations and temperatures when PL was added to boiled noodles in a simple wrapper. (1) At 20°C, pH of boiled noodles with PL was almost constant during 6-day storage time. On the other hand, pH of noodles without PL (control) decreased from 6.4 to 4.0 after 2 days. (2) At 20°C, viable cell counts gradually increased from 10²/g to 10³/g-10⁵/g during 6 days in the presence of 0.25% to 1.0% of PL, but the counts of control rapidly increased to more than 10⁶/g after 2days. (3) Yeast and mold counts in the samples with PL increased gradually from 10²/g to 10⁴/g-10⁵/g during 6days at 20°C. On the other hand, those of the control showed an increase to 10⁶/g or over after 2 days. (4) About 75% of PL remained in boiled noodles after cooking for 15min in boiling water. (5) The above results showed that the addition of PL was able to prolong shelf-life of boiled noodle for a few days as compared with non-added noodles.

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Effect of dough prepared by low temperature and long time fermentation on the qualities of bread was investigated through the experiment of orthogonal L₁₆ design with twelve factors by taking at two or six levels. The taste, flavor, texture, hardness, cohesiveness, springiness and specific volume of bread were measured and the data were estimated by variance analysis. The experimental results showed that fermentation at 10°C, 19 hr followed by 38°C, 30min and baking at 205°C, 30min could be recommended conditions for breadmaking. It was also found that a product with good taste and flavor could be obtained by 1.5% of yeast, 0.15% of dough conditioner, 2% of salt, 4% of sugar, 5% of shortning and 63% of water.

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The purpose of this paper is to define objective indices for quality evaluation of dried laver. The relation between physicochemical properties and organoleptic judgement was examined by analyzing 127 samples obtained from 10 culture grounds. The results are summarized as follows: (1) The correlation were significant at 1% probability level between sensory scores and 8 physicochemical values; chlorophyll a, total nitrogen, amino nitrogen, taurine, total free amino acid, color value L^*, b^*, and color (10/XX: trisutimulus values). (2) Physicochemical data were treated by principal component analysis. The variables employed were chlorophylla, total nitrogen, amino nitrogen, total free amino acid, 13 free amino acids (taurine, aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, isoleucine, leucine, phenylalanine, lysine, arginine), color value L^*, a^* and b^* (20 variables). The analytical results showed that the samples were classified into two groups in agreement with the classification of quality (high and low) on the basis of organoleptic judgement.

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Emulsifying properties of globin obtained from slaughtered porcine blood were investigated from the standpoint of the practical application in food processings. Though globin had high emulsifying capacity in the acidic region from pH 1.0 through pH 6.0 and at 50-70% oil volume, the capacity was extinguished by the addition of 3% NaCl. Emulsifying capacity of globin was as high as those of proteins such as porcine plasma, casein, soy protein and egg white at pH 3.0. In addition, the mixture of globin and porcine plasma (2:1) emulsified 60% salad oil at alkaline pH (pH 9.0) although globin showed high emulsifying capacity only in the acidic region. The animal fats, such as lard and beef tallow, were emulsified by the addition of 1% globin, but further addition of globin resulted in a decrease of the emulsifying capacity. The emulsion formed by globin was stable to heating at 80°C for 30min and cooling at 10°C for 4 weeks, however it was unstable to freezing at -20°C for 7 days. These emulsifying properties of globin may be capable of using as an acidic emulsifier in food processings.

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