Production of aroma compounds from whey using Wickerhamomyces pijperi

The production of aroma compounds by the microbial fermentation of whey was studied. Seven strains of the yeast Wickerhamomyces pijperi were used for the fermentation of glucose-added whey (whey-g). Twelve aroma compounds (isobutanol, isoamyl alcohol, 2-phenylethanol, acetaldehyde, ethyl acetate, propyl acetate, isobutyl acetate, isoamyl acetate, ethyl butyrate, ethyl propionate, ethyl hexanoate and ethyl benzoate) were identified in the fermented broth using headspace gas chromatography mass spectrometry analysis. The major components were ethyl acetate (several tens to hundreds ppm), acetaldehyde (several tens ppm) and isoamyl alcohol (about 10 ppm). The strong fruity odor of ethyl benzoate (about 1 ppm) was detected in the broth of W. pijperi YIT 8095 and YIT 12779. The balance of aroma compounds produced was varied depending on the media used, and ethyl benzoate was only produced when using whey-g. The variation in the production of the aroma compounds over time using W. pijperi YIT 12779 at various culture temperatures (from 15–30°C) was also studied. From the results we propose that W. pijperi could be used as a novel microorganism for production of aroma compounds from whey.