Cereal Chem 66:283-288   |  VIEW ARTICLE

Reversed-Phase High-Performance Liquid Chromatography Analysis of Changes in Free Amino Acids During Wheat Bread Dough Fermentation.

C. Benedito de Barber, J. A. Prieto, and C. Collar. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Qualitative and quantitative changes in 22 free amino acids (AA) during wheat bread dough fermentation were determined by reversed-phase high-performance liquid chromatography (RP-HPLC) of their dansyl derivatives in unfermented and fermented straight doughs. With 0-6 hr of fermentation, most major free AA (especially aspartic and glutamic acids, asparagine, and alanine) decreased, although proline did not. As a result, total AA content was depleted by 72%. In addition, free amino acids were metabolized at different rates. Glutamic acid, glycine, gamma-aminobutyric acid, and basic AA contents were significantly reduced with 2.5-6 hr of fermentation, whereas asparagine, dicarboxylic acids, hydroxy, aromatic, and monoamino monocarboxylic AA contents decreased first (before 2.5 hr). Between 6 and 24 hr of fermentation, total AA content increased (+105%) because yeast growth stopped and proteolytic activity from lactic acid bacteria increased. Increased alanine, glutamic acid, and proline accounted for 75% of the increase of total AA content during this period.