The purpose of this study was to gain an understanding of temporal trends in the mastication ability of children in their growth period and to clarify associated physical conditions, dietary intake, and physical fitness. The subjects were 34 junior high school and high school students. The amount of eluted sugar in chewing gum was used as an index to assess the mastication ability. For the boys, mastication ability positively correlated with height, weight, skeletal muscle mass, bone mass and lean body mass, breakfast, carbohydrates, calcium, iron, dietary fiber, grip strength and sit-up rate. In contrast, it negatively correlated with energy from morning snacks and reaction time. The results showed that better physical condition, regular breakfast eating, and greater muscle strength and agility increased the mastication ability. On the other hand, snacking lowered mastication ability. Individual differences in the mastication ability of girls were small and, therefore, no significant relationships were observed.

  The properties of red glutinous rice steamed using gas and induction heating were compared to clarify the different effects of the two heat sources on steaming. Gas heating resulted in no significant differences in moisture content, hardness, adhesiveness or degree of gelatinization between rice from the center of the steamer and rice from the periphery. With gas heating, the side temperature of the steamer became high, so the temperature at the peripheral part of the upper pot was higher than the temperature at its center. However, since some of the steam became superheated, the extra water was not presumably condensed on the rice surface. When the rice was steamed using induction heating, its moisture and hardness when collected from the periphery of the steamer were 54.3％ and 0.60×10⁵ Pa, respectively. The moisture and hardness at the center were 58.6％ and 0.52×10⁵ Pa, respectively. Thus, significant differences were found between the center and the periphery. Namely, the rice from the center had higher water content and was softer than the rice at the periphery. With induction heating, only the bottom of the steamer became hot, making it difficult for the temperature to rise at the side. Therefore, the temperature at the peripheral part of the upper pot was lower than the temperature at its center. These phenomena were regarded as the reasons why the rice was not steamed uniformly with induction heating.

  The aim of this study is to assess the sensory characteristics of cooked rice by TDS and CATA. Koshihikari, Milky Queen, low-protein rice, and Sasanishiki were used as samples. The sensory characteristics of these samples were different from each other in TDS and CATA, especially those of the low-protein rice. For low-protein rice, “sticky” and “pasty” were selected more often than the other sensory attributes in TDS, and “disliked taste” and “adhesive” were selected frequently in CATA.

  The relationship between the results in TDS and those of CATA was analyzed by the canonical correspondence analysis, by which it was shown that there were many similarities between them.

  In this study, the physical characteristics of cooked rice were also measured, and structural observation was carried out.