2006 Volume 101 Issue 9 Pages 711-716
A high-ethyl caproate-producing strain, Saccharomyces cerevisiae strain 3703-7, was isolated from cerulenin-resistant mutants of sake yeast. The strain produced a large amount of ethyl caproate when it was grown on a 15% glucose concentration and at 25° C. A much higher yield of ethyl caproate was produced from sucrose or fructose than from glucose added as a substrate. On the other hand, glucose concentration and growth temperature were not effective for the production of ethyl caproate by the parent strain 3703. From these results, it was suggested that strain 3703-7 produces ethyl caproate, ethyl acetate, and isoamyl acetate from the apple pomace extract containing sugars composed of glucose, fructose, and sucrose. The strain 3703-7 was grown in the apple pomace extract containing 6.4% and 10.4% sugars at 25°C. Ethyl caproate was produced in a much larger amount in the 10.4% than the 6.4% sugars. After 8 days of incubation in the pomace extract containing 10.8% sugars at 25°C, 5.23% of ethanol was produced, and the production amounts of ethyl caproate, ethyl acetate and isoamyl acetate were 3.12 ppm, 7.13 ppm, and 0.45 ppm, respectively. The distilled liquor had the flavor of alcohol containing 32.3% ethanol, possessing a sweet aroma typical of ethyl caproate in addition to an apple flavor.
