Saké Brewing Using the Liquefied Product of Rice Slurry as Raw Material (Kakemai)

Treatment of Rice in Saké Brewing. Part V

Abstract

An efficient saké brewing method was developed using the liquefied product after digestion of powdered polished rice slurry with bacterial alpha-amylase. Almost all the starch was liquefied with bacterial alpha-amylase and converted into alcohol in the moromi, so that a larger amount of sake was produced than from polished rice grain or from powdered polished rice. As solid phase dissolution was not high and the liquid phase volume was stable during fermentation, glucose production rate(dG/dt)was expressed as a function of three parameters (initial glucoamylase activity (E), substrate concentration (S) and temperature (T)), namely, dG/dt=a•k₀•E₀•exp[k_t/T-k_d•t exp(k_dt/T)]•(S)/[(S)+Km+(S)+(S)²/Ki]. With this equation, the glucose production rate was successfully estimated during fermentation.