Flavor precursors vital for gluten-free bread aroma: Study

Gluten-free bread can be enhanced with amino acid and sugar pairs ahead of baking to improve aroma in the final product, researchers find.

Published in LWT Food Science and Technology, researchers investigated the cause of “weak aroma” in gluten-free breads and how this could be improved.

Analysis showed gluten-free breads lacked certain flavor compounds that were key to the aroma of regular wheat bread, specifically pyrazines and 2-acetyl-1-pyrroline (2ACP).

Wheat bread contained 41 volatile compounds; wheat rye contained 54 and gluten-free only 33.

“Differences were mainly related to the volatile compounds contained in the crust of the bread,” the researchers wrote.

“…So far, gluten-free bread has not been analyzed in terms of the volatile compounds it contains, but this feature is a vital factor for the quality of the product from the consumer’s point of view.”

They said unpleasant sensory notes in gluten-free bread might also be associated with high levels of methional that tends to have a potato-like odor.

Amino acids and sugar

However, the researchers said these compound deficiencies in gluten-free bread could be resolved with the addition of amino acids and sugars to the bread mix.

After testing five amino acid/sugar pairings, the researchers found proline combined with glucose to be most efficient.

These precursors, they explained, combined to create the aromatic compound 2ACP – normally not present in gluten-free bread.

“The addition of aroma precursors of Maillard reaction in the dough prior to baking, as a pair of proline and glucose, filled this shortcoming and allowed bread with a much improved and acceptable aroma to be produced,” they wrote.

In consumer testing with celiacs, 80% preferred the gluten-free breads made with these aroma precursors.

“This confirmed the effectiveness of aromatizing gluten-free bread using proline/glucose as flavor precursors,” the researchers wrote.

Source: LWT Food Science and Technology

Published online ahead of print, doi: 10.1016/j.lwt.2015.03.032

“Improving the aroma of gluten-free bread”

Authors: M. Pacynski, RZ. Wojtasiak and S. Mildner-Szkudlarz