The length of rice crack during water absorption was quantitatively evaluated. Images of rice during water absoption were taken by digital microscope, and these images were analyzed by ImageJ. Changes in total crack length were possible to approximate accurately by logistic equation. Maximum total crack length and the increase rate for total crack length were defined by the parameters of a logistic equation model. The increase rate for total crack length was positively correlated with the initial water absorption rate. This suggested that the increased area contacting water by the occurrence of crack affected the water absorption ratio. Maximum total crack length was negatively correlated to the storage modulus. It was found that rice crack softened steamed rice. These parameters arising from the occurrence of crack were negligibly correlated to gelatinization temperature, but passively correlated to the starch solubility in the digestion test of steamed rice. It was estimated that the increased disintegration of steamed rice by crack occurrence contributed to the increase in the solubility of steamed rice.
This study suggests a possibility for a support system for the actual manufacturing process of Sake by using mathematical model of simultaneous saccharification and fermentation, data assimilation, and model prediction control. Demonstration of the actual prediction was conducted in order to evaluate the effectiveness of the proposed support system. In the demonstration, we predicted the actual manufacturing process of Sake by using actual measurement data provided by Asahi Shuzo. As a result, it appears possible to predict the manufacturing process and optimize the management process of temperature and addition of water.