THERMAL CONTROL STRATEGY FOR ISOAMYLACETATE FORMATION IN SAKE BREWED WITH A SACCHARIFIED RICE SOLUTION

Isoamylalcohol and isoamylacetate concentrations were analyzed at various isothermal conditions in sake brewed with a saccharified rice solution. Kinetic models for formation of these components were constructed in which the relation between the isoamylalcohol and ethanol formation rates were linear, and the isoamylacetate formation rate was expressed as the sum of two terms, formation and decomposition. An optimal control strategy for isoamylacetate formation was calculated using dynamic programing. The calculations suggested that the fermentation temperature should be gradually lowered as the fermentation progresses in order to maintain the isoamylacetate formation rate at a high level.