Impact of Malt Extract Addition on Odorants in Wheat Bread Crust and Crumb

Application of gas chromatography-olfactometry and aroma extract dilution analysis to the volatiles isolated from (1) crust and (2) crumb of a wheat bread made with the addition of a dark liquid malt extract (LME) to the dough and (3) crust and (4) crumb of a reference bread made without addition resulted in the identification of 23 major odorants. Their quantitation followed by the calculation of odor activity values (OAV = ratio of concentration to odor threshold value) suggested that LME addition influenced the aroma of the bread predominantly by increasing seasoning-like smelling sotolon in crust and crumb, and caramel-like smelling compounds maltol and 4-hydroxy-2,5-dimethylfuran-3(2H)-one (HDMF) in the crumb. The increase in sotolon and maltol was explainable by direct transfer from the LME to the bread, whereas HDMF must have been formed from LME-derived precursors. This difference needs to be considered in the targeted optimization of LMEs for bread making.

Automated summary

The use of gas chromatography-olfactometry and aroma extract dilution analysis on wheat bread samples with and without the addition of dark liquid malt extract (LME) showed that LME addition primarily increased the levels of sotolon, maltol, and HDMF in the bread, with sotolon and maltol possibly transferring directly from the LME to the bread, while HDMF appeared to be formed from LME-derived precursors. This difference should be taken into account when optimizing the use of LMEs in bread making.