Production of Apple-like Aroma by Geotrichum sp. Isolated from Sludge

A strain producing apple-like aroma was isolated from sludge and identified as Geotrichum sp. Optimum culture conditions for the aroma production were investigated and the major aroma components were identified by GS and GC-MS. The ratio of leucine to phenylalanine was 100:1 (1.5 g/l) and ethanol concentration was 0.5-1.0% (v/v). The best aroma quality was obtained at and pH 4.0. Major aroma compounds were alcohols including 3-methylbutyl alcohol, phenetyl alcohol, 2-hexene-1-ol and their esters, and esters originated from ethyl alchol.