Characterization of the Major Odorants in Beer Brewed with <i>Torulaspora delbrueckii</i> ─Differences to Beer Brewed with <i>Saccharomyces cerevisiae</i>

While the influence of different malts and hop varieties on the aroma of beer has been well studied, there are still significant gaps in our knowledge regarding the contribution of non-Saccharomyces yeasts to beer aroma. Sensory evaluation showed a more intense fruity note in a beer brewed with Torulaspora delbrueckii compared to a beer brewed with Saccharomyces cerevisiae. The application of a comparative aroma extract dilution analysis resulted in 32 odorants, 26 of which exceeded their odor threshold concentrations in the T. delbrueckii beer. Among them were the fruity smelling esters ethyl butanoate, ethyl 2-methylpropanoate, and ethyl propanoate, all of which showed lower odor activity values in the S. cerevisiae beer. Their decisive role in the fruitiness of the T. delbrueckii beer was confirmed in a spiking experiment.