Unlocking the Functional Potential of Pecan Nut Cake: A Study on Bioactive Peptide Production

This study examined whether co-fermentation with <i>Lactobacillus casei</i> CGMCC 15956 and <i>Lactobacillus delbrueckii</i> CGMCC 21287 could enhance the bioactivity of peptides derived from pecan nut cake (PNC) and clarify the underlying mechanisms. The fermented hydrolysate (PNCH) was compared with an unfermented control. PNCH showed higher antioxidant and α-glucosidase inhibitory activities. Total antioxidant capacity increased from 3.17 to 4.81 mM Trolox, and DPPH radical scavenging activity increased from 62.69% to 84.12%. In addition, the IC₅₀ value for α-glucosidase inhibition decreased from 7.549 to 4.509 mg/mL. In a mouse model of acute alcohol-induced liver injury, PNCH significantly alleviated liver damage through the synergistic enhancement of antioxidant and α-glucosidase inhibitory activities. Peptidomic analysis identified two representative bioactive peptides, FAGDDAPR (from actin) and LAGNPDDEFRPQ (from cupin domain-containing protein 1), both of which exhibited antioxidant and α-glucosidase inhibitory activities. Additionally, these peptides alleviated H₂O₂-induced oxidative stress in Caco-2 cells, significantly improving GSH and MDA levels, as well as SOD activity. Molecular docking suggested potential interactions of these peptides with superoxide dismutase, Keap1, and α-glucosidase. These findings support the high-value utilization of PNC and the development of functional peptide-based ingredients.