Antioxidant Peptides from Sacha Inchi Meal: An In Vitro, Ex Vivo, and In Silico Approach

Plant-derived antioxidant peptides safeguard food against oxidation, helping to preserve its flavor and nutrients, and hold significant potential for use in functional food development. Sacha Inchi Oil Press-Cake (SIPC), a by-product of oil processing, was used to produce Sacha Inchi Protein Concentrate (SPC) in vitro, hydrolyzed by a standardized static INFOGEST 2.0 protocol. This study aimed to integrate in vitro, ex vivo, and in silico methods to evaluate the release of antioxidant peptides from SPC during gastrointestinal digestion. In vitro and ex vivo methods were used to investigate the antioxidant potential of SPC digests. Bioinformatics tools (find-pep-seq, AnOxPP, AnOxPePred-1.0, PepCalc, MLCPP 2.0, Pasta 2.0, PlifePred, Rapid Peptide Generator, and SwissADME) were employed to characterize antioxidant peptides. The gastric and intestinal digests exhibited higher ABTS and ORAC values than those of SPC. Under basal conditions, gastric digest fractions GD1, GD2, and GD3 (<3, 3-10, and >10 kDa, respectively), separated by ultrafiltration, significantly reduced the ROS levels in the RAW264.7 macrophages while, under LPS stimulation, GD1 (16 mu g/mL) and GD2 (500 and 1000 mu g/mL) reversed the induced damage. From the de novo peptidome determined, 416 peptides were selected based on their resistance to digestion. Through in silico tools, 315 resistant peptides were identified as antioxidants. Despite low predicted bioavailability, the peptides SVMGPYYNSK, EWGGGGCGGGGGVSSLR, RHWLPR, LQDWYDK, and ALEETNYELEK showed potential for extracellular targets and drug delivery. In silico digestion yielded the sequences SVMGPY, EW, GGGGCGGGGGVSS, PQY, HGGGGGG, GGGG, HW, and SGGGY, which are promising free radical scavengers with increased bioavailability. However, these hypotheses require confirmation through chemical synthesis and further validation studies.