Rate of Temperature Change with Five Pot and Pan Materials according to Bottom Thickness The rate of temperature change during the processes of heating and air cooling was studied for pots and pans in five different materials with varying bottom thickness. Although the shape and sizes of the pots and pans have differed, remarkable correlation has been observed between the rate of temperature change and bottom thickness, as well as with such thermophysical properties of the materials as the thermal conductivity, specific heat capacity and thermal diffusivity. The rate of temperature rise during heating decreased with increasing botto m thickness, and did the rate of temperature drop during air cooling. Thick pans took 2 to 5 times longer to heat than thin pans. The rate of temperature rise for pots and pans made from Al-alloy and Cu materials, which have high thermal conductivity, was lower than the rate of temperature drop. On the other hand, the rate of temperature drop was lower than that of temperature rise for the pots and pans in carbon steel, stainless steel and heat-resisting glass materials which have relatively low thermal conductivity. The rate of external temperature rise for the Al-alloy and Cu materials detected at heater outside was much higher than that for the carbon steel, stainless steel and heat-resisting glass materials, while the difference in temperature for the Al-alloy and Cu materials between the heater inside and outside was much smaller than that for the carbon steel, stainless steel and heat-resisting glass materials.
Coagulation by heating and the emulsifying properties of Nagoya-Cochin eggs were compared with those of White Leghorn eggs. The hardness and cohesiveness of the egg white and yolk coagulated by heating in boiled eggs, and the texture and creep properties of the whole egg in sweet rolled omelettes were determined. The egg white and yolk of boiled eggs and of the sweet rolled omelettes from Nagoya-Cochin eggs were harder than those from White Leghorn eggs. Furthermore, the sweet rolled omelettes from Nagoya-Cochin eggs were more elastic than those from White Leghorn eggs. This confirms that the gel of Nagoya-Cochin eggs was firm and elastic. The lipid particle size in the emulsion prepared from Nagoya-Cochin eggs was smaller than that from White Leghorn eggs.
The effect of sugar structure on the gloss produced by heating was examined by using a new evaluation model that requires only a small amount of the sample. Ground glass discs (1.5cm2)coated with 30 μl of 1% of various kinds of sugar solution were heated at 180±5°C. After cooling, the gloss of the sugar coating was measured by using a VG-2000 gloss meter (Nippon Denshoku Co. Ltd. ) at alight incidence angle of 60°. After testing the usefulness of this model, the effects of various sugars having different configuration and polymerization on the gloss produced by heating were examined. Among the monosaccharides tested, the gloss level of the glucose coating was the highest. Among the α-linked glucobios esugars, the gloss was highest in order of1→6>1→4>1v3>1→2>1→1. The gloss level of the coatingsby α-linked oligosaccharides was higher than those by β-linked oligosaccharides. The effects of the polymerization of glucose and the amino-carbonyl reaction were also examined.
The effects of the cooking conditions (heating temperature, pH value and NaCl concentration) on the gelation properties of savory cup custard (chawan mushi) were examined by dynamic viscoelasticity measurements. The gelation tmperature of the egg solution (0.6% NaCl, pH 6.45) was 77°C, and the storage modulus (G')and loss modulus(G') both increased with increasing heating temperature to 90°C. Increasing the heating ratio resulted in a higher gelation temperature and lower G'value. However, the most desirable physical properties of chawan mushi prepared by heating to a final intemal temperature of 90°C were obtained regardless of the heating ratio. The G'value increased with increasing pH from 5.2 to 7.0 and reached a constant value at above pH 7.0, and the resulting ratio of free water decreased under the alkaline pH condition. G'also increased with increasing NaCl concentration from 0.6% to 1.2%. The product with a 0.8% NaCl concentration was favored over that with a 0.6% concentration in the panel test.
The effect of adding red wine on the cooking properties of newly developed rice varieties was studied. The new varieties of aromatic rice, high-yield rice, and different amylose content rice were cooked, and the water uptake ratio, expanded volume, and iodine blue value were measured. The physical properties of the cooked rice samples were analyzed by a Tensipresser, and the sensory characteristics of the cooked red wine rice were evaluated for the “relative strength” and “palatability.” The addition of red wine resulted in a lower water uptake and expanded volume, and higher iodine blue value for all the rice varieties examined. Red wine increased the firmness of the cooked rice, and the firmness increased with increasing quantity of red wine added. The adhesiveness of the cooked red wine rice samples was about the same as that of the normally cooked rice when the red wine was added just before cooking. Aromatic rice, Kanto 172, exhibited increased color, luster and smell when 30% of red wine was added, and was preferred for its luster in the sensory evaluation.
Four new local varieties of rice, Tsugaruotome, Hanaechizen, Hinohikari and Higonohana, have been developed by cross-breeding with such typical rice varieties as Koshihikari, Sasanishiki and Nipponbare. The purpose of this study is to determine the effect on the cooked rice taste of cross-breeding with rice cultivars which have high eating quality. The rice varieties cross-bred with Koshihikari, named Tsugaruotome and Hanaechizen, were lower in apparent amylose content than Hinohikari and Higonohana which were cross-bred with Nipponbare. There was no difference in the increase in weight and water content of the cooked rice among these four varieties. The degree of gelatinization of the cooked rice cross-bred with Koshihikari was slightly higher than that of the other two varieties. The hardness and adhesiveness of cooked Tsugaruotome, Hanaechizen and Hinohikari were similar to those of Koshihikari. Hanaechizen and Tsugaruotome both showed high quality in the taste evaluation of cooked rice. These results indicate that the texture and taste of cooked rice was enhanced by cross-breeding other varieties with Koshihikari. But the texture and taste were no better than those of Koshihikari.
The purpose of this paper is to examine the transition in meanings encompassed by the term “cookery”that appeared in 179 homemaking textbooks for high school and college students from 1888to 1994 in Japan. “Cookery” included 47 activities or concepts that we categorized and counted by representative key words. 1. In textbooks published before 1946, there were no distinctive differences between the terms shokuhin and shokumotsu. The purposes and significance of cookery were mainly explained by the key words: to kill microorganisms or parasites, to satisfy nutritional needs, to make foods more digestible, to make foods more appealing in appearance, and to improve taste to stimulate appetite. 2. In high school textbooks published during the past 50 years, cookery involved some of the same key words: preparing hygienically safe food, improving nutritional density, making foods more digestible, and making foods better in appearance. Other than these, processing food to make it easier to eat or digest, and making food tastier were also frequently used as key words. 3. In college textbooks published from 1953 to 1994, the differences between shokuhin and shokumotsu were clearly defined. The purpose of cookery encompassed more key words than those used earlier (and mentioned above). Added to the key words of-making food easier to eat and digest, preparing hygienically safe food, improving nutritional density, improving palatability and taste, and making foods better in appearance-were the important concepts of continuing cultural (and regional)traditions, and creating a happy and safe home atmosphere through the preparation of good meals.
The radical-scavenging activity of 118 commercial beverages (coffee drink, cocoa drink, tea drink, fruit juice and beverage, vegetable juice, milk beverage, soybean milk beverage, carbonated drink, near-water beverage, etc. ) was evaluated by using the 1,1-diphenyl-2-picrylhydrazyl radical. The contribution of ascorbic acid to this activity was also determined. Coffee and cocoa drinks without ascorbic acid showed the highest level of activity. Tea drink prepared from tealeaves had high activity, the contribution of ascorbic acid to this activity being about 20%. Fruit and vegetable juices showed the mid-level activity among the samples tested, the contribution of ascorbic acid being mainly 20-70%. Nutritional, near-water and carbonated drinks showed various levels of activity depending on the amount of ascorbic acid added.