Trehalose has been used in the foods, pharmaceuticals, and cosmetics industries due to its multifunctional properties. The aim of this study was to elucidate the effect of trehalose as a partial replacement of sugar on the physicochemical properties of the brown rice tofu during storage. As a result, the L* values for the brown rice tofu without trehalose addition and with the application of 1% trehalose decreased significantly with the passage of the storage day. In contrast, 10% trehalose replacement provided a marked positive effect on the color retention of the brown rice tofu, especially whiteness index, suggesting the prevention of the browning of the brown rice tofu. The water content of the brown rice tofu with incorporation of 10% trehalose was significantly high when compared with other tested brown rice tofu after 7 days of storage, resulting in suppression of the hardening of the brown rice tofu. In addition, the incorporation of trehalose could be suppressed the microbial growth on the brown rice tofu. This study proved that a partial replacement of sugar with trehalose, especially 10% trehalose, could be beneficial on the prevention of the quality degradation and improvement of the shelf life, such as prevention of the browning and suppression of the hardening and microbial growth of the brown rice tofu during storage.

The objective of this study was to develop brown rice tofu using kudzu and the non-glutinous rice cultivar Haenuki and glutinous rice cultivar Himenomochi produced in Yamagata prefecture. The apparent amylose contents of the starches from Haenuki, Himenomochi, and kudzu were approximately 18.0 %, 0 %, and 26.1 %, respectively. Next, the brown rice samples were roasted and milled. Flour particles with a size>212 µm were the most abundant, and the damaged starch contents of these flours were low at approximately 5.1 % to 5.2 %. The water absorption rate of the rice flour samples gradually increased at 50 ℃ to 70 ℃. In contrast, that of kudzu flour drastically increased at 60 ℃ to 100 ℃. Brown rice tofu could be produced when 7.5 g or 15.0 g of the rice flours were used. The b * values of these tofu samples increased with increasing flour content. By textural analysis, a low breaking strength in Himenomochi tofu and high adhesiveness in Haenuki tofu were observed when 15.0 g of the flour samples were used, indicating an increase in softness and stickiness, respectively. Additionally, sensory analysis revealed that 15.0 g of Haenuki flour was the most appropriate for the production of brown rice tofu among the tested tofu. These results may provide useful information for >kawari tofu< industries.

The purpose of this study was to investigate the applicability of starches from various botanical sources as a substitute for kudzu flour in the production of brown rice tofu. In sensory analysis, potato starch and tapioca starch were suggested as a possible alternative to kudzu flour among the tested starches. Additionally, textural analysis indicated that the adhesiveness of the tofu prepared using potato starch was remarkably high when compared with that using tapioca starch. Thus, it was revealed that tapioca starch was the best substitute for kudzu flour in brown rice tofu production.

The aim of this study was to improve the quality of brown rice tofu to produce it with a superior-quality. When the brown rice flour was heat treated with water, the water absorption rate of flour decreased using brown rice flour with a particle size range of &lt; 212 &mu;m when compared with that of brown rice flour with a particle size range of &lt; 475 &mu;m. The cohesiveness and gumminess of brown rice tofu made from brown rice flour with a particle size range of &lt; 212 &mu;m were fairly high in comparison with those of brown rice tofu made from brown rice flour with a particle size range of &lt; 475 &mu;m. In addition, the adhesiveness and cohesiveness of brown rice tofu remarkably decreased when heating and kneading times of brown rice flour dough were extended. By textural and sensory analyses, it became clear that the use of brown rice flour with a particle size range of &lt; 212 &mu;m and the extension of gelatinization time and heating and kneading times of the dough were important factors for preparation of high-quality brown rice tofu. Therefore, the results indicated that it could produce acceptable high-quality brown rice tofu having smooth and new palate feeling while suppressing adhesiveness and stickiness peculiar to rice flours.