A complete workflow for discovering small bioactive peptides in foods by LC-MS/MS: A case study on almonds
Journal
Food Chemistry
Journal Volume
369
Start Page
130834
Date Issued
2022-02
Author(s)
Abstract
Identification of bioactive peptides is an increasingly important target for food chemists, particularly in consideration of the widespread application of proteolytic enzymes in food processing. Because the characterization of small peptides by LC-MS/MS is challenging, we optimized a dimethyl labeling technique to facilitate small peptide identification, using almond proteins as a model. The method was validated by comparing the MS/MS spectra of standards and almond-derived peptides in their nonderivatized and derivatized forms. Signal enhancement of a1 ions was proved to effectively aid in the full-length sequencing of small peptides. We further validated this method using two industrially-relevant protein-rich extracts from almond flour: 1737 medium-sized peptides (5–39 amino acids) and 843 small peptides (2–4 amino acids) were identified. The use of an online bioactive peptide database, complemented by the existing literature, allowed the discovery of 208 small bioactive peptides, whereas for medium-sized peptides, only one was reported being bioactive.
Subjects
Almonds (Prunus dulcis)
Bioactive peptides
Di- and tripeptides
Dimethyl labeling
Enzymatic protein hydrolysis
Peptidomics
Type
journal article