Ferulic acid’s effect on whole wheat bread aroma

January 16, 2013

A study published in the Journal of Agricultural and Food Chemistry shows that tweaking amounts of ferulic acid in whole wheat bread can alter the flavors and aromas.

Whole wheat flour includes all three layers of the grain—bran, germ, and endosperm—while refined flour is mostly endosperm. Whole wheat flour contains more fiber and compounds called phytochemicals, both of which can help reduce the risk of cancer, heart disease, diabetes, and obesity. Despite wheat bread’s benefits, many consumers choose white bread because they prefer its taste and aroma. The outer layers of bran and germ that remain in whole wheat flour tend to create products that taste, smell, and look less-than-appealing to many people.

As part of an effort to understand the chemistry that distinguishes whole grain bread from refined grain versions, the researchers made bread with both kinds of flour and then analyzed the compounds in each loaf’s aroma. A panel of trained sensory analysts also sniffed samples of ground-up crust to characterize the differences.

The team focused on ferulic acid, which is normally bound to wheat’s cell walls but is set free during fermentation and baking. Only after it is liberated does it begin to alter the flavor and smell of bread. When the researchers added ferulic acid to refined grain bread, they found that its aroma resembled that of whole wheat bread. Ferulic acid appears to suppress a compound called 2AP, which is the most important molecule behind whole wheat bread’s unique smells.

This finding shows that ferulic acid plays a key role in producing the aroma of whole wheat bread. By minimizing the liberation of ferulic acid during baking, the study suggests, it might be possible to alter the taste of the final result—eventually making whole-grain bread that is more satisfying to people who prefer white loaves.