Food models were used to investigate the relationship between unfreezable water in food and microwave thawing. Solution food models were prepared including glucose (10, 20, 30%) and dextran (10, 20, 30%) solutions. No substantial differences were observed in the heating rate among unfrozen samples when reheated by microwave, but substantial differences were observed among the frozen solution samples when heated, thereby, suggesting an impact of difference in the ice fraction. Using ice fraction as a factor, the relative microwave heating rate was theoretically calculated to determine the cause of the differences in the heating rates among the frozen samples.

　The effects of heat treatment and freezing on the physical properties of bean sprouts were analyzed by measuring the electrical impedance, optical absorbance of an aqueous solution containing bean sprouts, and dynamic elasticity. Additionally, textural properties were also analyzed by the bending shear test. During freezing, the electrical impedance and dynamic elasticity changed dramatically due to a serious injury to the cell structure of bean sprouts. During the heat treatment, the impedance of bean sprouts began to decrease at around 40℃ due to injury to the protoplasm membrane. Changes in the optical absorbance and dynamic elasticity were observed at the temperatures higher than 50℃. In the bending shear test, a fresh sample showed a high instantaneous elasticity along with a small deformation before destruction, while a frozen-thawed sample showed a small instantaneous elasticity with a large deformation before destruction due to the softening of the cell structure.

　'Awabancha' was one of post fermented tea produced in some area in Tokushima prefecture. In this study, we isolated and identified bacterial strains from tub for 'Awabancha' fermentation, and clarified mechanism of regulation of bacteria in fermentation period. The number of lactic acid bacteria (LAB) was 10⁷ cfu/mℓ and general bacteria ranged from 10⁶ to 10⁸ cfu/mℓ. In addition, the pH and polyphenol content in tub was ranged from 4.9 to 7.4 and from 0.17 to 3.15mg/mℓ. Bacteria except for LAB grew in weakly alkaline and low polyphenol content (＜0.55mg/mℓ). The results showed that polyphenol was regulator of general bacteria except for LAB. This information may one of idea for control of quality of 'Awabancha'.