Key aroma compounds formation during preparation of pumpernickel bread.

Application of gas chromatography - olfactometry analysis (GCO) to pumpernickel bread and its intermediate products obtained during fermentative process allowed to recognize 32 key aroma compounds with specific odor notes. Subsequent quantitation using stable isotope dilution assay analysis (SIDA) and calculation of odor activity value (OAV) revealed 22 compounds with OAV>1; with the highest OAV value for 3-methylbutanal with malty odor (6660), 2 methyl butanal with malty odor (4560), methional with boiled potato odor (2047), 3-hydroxy-4,5-dimethyl-2(5H)-furanone with lovage-like odor (1233), dimethyl trisulfide with cabbage odor (475), 2-phenylethanol with rosy odor (414), β-damascenone with boiled apples (200), vanillin with vanilla odor (184), 4-hydroxy-2,5-dimethyl-3(2H)-furanone with caramel odor (172) and phenylacetladehyde with honey odor (100). The results showed that aroma of pumpernickel bread is mostly formed during baking however fermentation process influences formation of several compounds, such as: ethyl acetate, 2,3-butanedione, acetic acid, 3-methylbutanol, ethyl butyrate, ethyl lactate, ethyl-3-methyl butyrate, ethyl hexanoate, phenylacetaldehyde and 2-phenylethanol. Furthermore addition of functional components such as malt and wheat fiber affects concentration of several key odorants in the final product such as 2 and 3-methylbutanal, maltol and vanillin.