Effect of lipase in the sake moromi brewing process

To examine the possibility of controlling the flavor of sake by enzyme addi tion, the effects of ten kinds of commercially available lipases on flavor production during sake moromi fermentation were investigated. The results s howed that lipase addition tended to increase the ethylcaproate content and decrease the isoamylacetate content. Among the lipases examined, Lipase PS had the most marked effect, and this lipase was selected for more detailed investigation. Six runs of sake moromi fermentation were carried out with varying amounts of Lipase PS. The results were as follows. The isoamylaceta te content drastically decreased in all runs, while the ethylcaproate conte nt increased with increasing lipase addition. Apart from isoamylacetate and ethylcaproate, other parameters were not affected. When lipase purified fr om Lipase PS was supplied during sake moromi fermentation, similar results to the above were obtained. No significant effects was observed when deacti vated lipase was added. Since purified lipase degraded both isoamylacetate and ethylcaproate in an in vitro experiment, the increase in ethylcaproate resulting from lipase addition appears to be a characteristic unique to sak e moromi fermentation.