Influence of commercial baker's yeasts on bread aroma profiles

- We explore the effect of fermentation with commercial baker's yeasts on bread aroma.
- Significant different fermentative activities between the baker's yeasts were found.
- Bread samples could be separated into five groups according to their aroma profile.
- Choice of baker's yeast is very important for the bread aroma and fermentation time.

Baker's yeast is used for bread fermentation throughout the world and it is very important for the bread quality. The scope of this work was to investigate how the aroma of wheat bread crumb is influenced by yeast fermentation by comparing the aroma formation of bread fermented by seven commercial baker's yeasts. Dough samples were fermented with equal number of yeast cells to equal height and then baked. The volatile components were extracted by dynamic headspace sampling and analyzed by gas chromatography mass spectrometry. The dough fermentation time varied significantly from 40 to 100 min. The fermentation compounds 2,3-butanedione and 1-propanol were found in significantly higher concentration in bread fermented with the four baker's yeasts having the shortest fermentation times. Furthermore, 3-methylbutanal, 2-methyl-1-propanol and ethyl acetate were found in significantly higher concentration in two of the yeasts. On the other hand phenylacetaldehyde and 2-phenylethanol were found in significantly higher concentration in bread fermented with two other yeasts. It can be concluded that use of the seven commercial baker's yeasts for bread fermentation resulted in significantly different bread aroma profiles.