The chemical components and cooking properties of 12 cultivars of Myanmar rice were studied for a comparison with eight cultivars of Japanese rice. This represents the first report to our knowledge on various cultivars of Myanmar rice. The range of physicochemical properties was much wider in Indica rice from Myanmar than in Japonica rice from Japan. The texture of cooked Indica rice was harder and less sticky than that of cooked Japonica rice. Adding more water to Indica rice did not increase itsstickiness when cooked, although the hardness was decreased. A sensory evaluation was conducted on the preference of cooked plain rice and rice for pilaf and curry. Japonica was preferred as plain cooked rice, while Indica rice was preferred for pilaf and curry. The sensory score could be expressed with the multiple regression equation by using instrumental measurement values for the cooked rice.
Sponge cakes were baked in a superheated steam oven and a steam-free convection oven to compare the quality of products cooked with superheated steam. The superheated steam markedly increased the heat transfer coefficient in the initial stage of heating. When compared withthe cake baked in the steam-free oven, the one baked in the superheated steam oven expanded more with visible cracking; moreover, its crust was darker and harder. Heating with superheated steam increased the rate of temperature rise on the surface of the cake, resulting in shorter baking time. The cake baked in the shortest time with superheated steam also showed cracking and a harder crust than that of the cake baked in the steam-free oven. The quality of sponge cakes baked with superheated steam was substantially influenced by the considerable transfer of heat during the initial stage of heating.
The conditions were investigated for producing a green tea infusion suitable for preparing cha-meshi with optimum green color and tea flavor. The following conditions were evaluated: tea concentrations of 1%,2%, and 3%, water temperatures for steeping of 5°C and 20°C, and steeping durations of 4,24, and 48 hours. The amount of floating particles in the infusion and the turbidity of theinfusion increased with increasing tea concentration, while the L* value decreased. The a* value of the infusion at 5°C changed little under the different conditions, and the green color was maintained, The arnount of catechins extracted at 5°C was less than that at 20°C. Cha-meshi contamed a quarter of the amount of catechins in the green teainfusion. Cha-meshi prepared with the tea infusion at 20°C had an inferior evaluation in terms of both its color and flavor. A steeping duration of 24 hours for the infusion of 2% tea concentration at 5°C produced cha-meshi with a strong green color and appropriate levels of tea flavor and astringency.
A questionnaire survey was conducted on the elderly throughtheir visual sense to investigate the colors that were hard to distinguish, and the favorite appearance of cooked food. The data from the color chart examination indicated that most of the subjects felt it hard to distinguish the hues of purple and yellow. The questionnaire survey on cooked food preference used photographs of stewed Japanese radish. The subjects preferred the appearance of those in round shape, in light colors and with soup. The results of survey on the distinction by the elderly of six kinds of stewed vegetable (edible burdock, potato, pumpkin, Japanese radish, carrot and taro) against four background colors using photographs suggested the influenceof the way the vegetables were cut and of the colors of dish.
Leafy, root, stalk and fruiting vegetables were heated by steam at a temperature adjusted between 55°C and 60°C for 5 and 20 min to study the effect of low-temperature steam heating on the free amino acids in various vegetables. The amino acid contents of the steamed vegetables were little different from those the fresh samples. Prolongation of the heating time resulted in glutamic acid tending to gradually decline, together with an increment in γ-amino butyric acid. The ratio of γ-amino butyric acid to the total amino acid conterlt in carrot and radish of the root vegetables and in tomato of the fruiting vegetables was notably higher than the ratio in theother vegetables studied in this experiment.
Sensory analyses of the two varieties of banana, a new variety of banana cultivated in highlands and the traditional variety were carried out to determine the preferenceof consumer and trained panelists for the analysis. The physicochemical properties were also determined. The new variety of banana was preferred by both consumers and trained panelists for its sweetness, firmness and richness of taste, while the traditional variety was preferred for its sweetness and softness, but not richness by consumer. The brix value, acidity firmness and adhesiveness of the new variety of banana were each higher than those of the traditional variety. These physicochemical data supported the data from the sensory analysis.