γ-Glu-Phe (γ-Glutamylphenylalanine) is a γ-3 glutamyl dipeptide found in sourdough.it is synthesized by Bacillus amyloliquefaciens (GBA) and Aspergillus oryzae (GAO). γ-Glu-Phe or the post-enzymatic reaction mixture enhances the umami intensity of commercial soy sauce and model chicken broth.

3-methoxybenzoic acid is a food additiveand has antibacterial activity.

Malic acid is a tart-tasting organic dicarboxylic acid that plays a role in many sour or tart foods. Apples contain malic acid which contributes to the sourness of a green apple.