Plum (Prunus Domestica L.) by-product as a new and cheap source of bioactive peptides: Extraction method and peptides characterization

Fruit processing produces a great amount of wastes. Stone of fruits such as plum (Prunus Domestica L.) are part of these residues. Plum stones contain a seed with a high content in proteins and lipids that are mostly underused and undervalued. This work proposes to extract proteins from this by-product, to evaluate their potential as bioactive peptide source, and to identify these peptides using RP-HPLC-MS/MS. A method for the extraction of plum seed proteins using high intensity focused ultrasounds has been developed. Extracted proteins have been digested using Alcalase, Thermolysin, Flavourzyme, and Protease P enzymes. Alcalase was the enzyme yielding the extracts with the highest ABTS radical scavenging capacity and lipid peroxidation inhibition capacity. It also showed a high capacity to scavenge hydroxyl radicals and to inhibit ACE enzyme. Analysis of the Alcalase extract by RP-HPLC-ESI-Q-TOF enabled the identification of short chain and highly hydrophobic peptides.