Enhancement of fruity aroma production of Pseudomonas fragi grown on skim milk,whey and whey permeate supplemented with C3-C7 fatty acids

Summary Pseudomonas fragi strain CRDA 037 produced a fruity aroma when grown in skim milk-, whey-and whey permeate-based culture media. The production of the odour-active metabolites was related to the lipid content of these media but was not influenced by the pH of the cultures. Analysis of the fruity aroma revealed that esters of fatty acids were some of the odouractive metabolites. Addition of C₃-C₇ fatty acids to the culture at 0 h stimulated the production of the corresponding fatty acid esters from 12 to 1570 times compared to unsupplemented media. Supplementation of the culture media with the C₃-C₇ fatty acids at 48 h, resulted in a 1.4- to 932-fold increase in the ethyl ester concentration.