Food-derived peptides have good antioxidant activity and are highly safe for humans; consequently, there has been continuous growth in research on antioxidants, with potential applications in food, medicine, cosmetics, and other fields. Among food-derived peptides, walnut-derived peptides have attracted increasing attention as food-derived peptides rich in eight essential amino acids. This review summarizes the progress made in the development and identification of antioxidant peptides in walnut proteins. This article mainly describes the interaction between reactive oxygen species and cellular antioxidant products, modulation of enzyme content and activity, and regulation of the redox signaling pathways and analyzes the mechanisms of reduction in oxidative stress. Finally, the complex structure–activity relationships of walnut-derived peptides are analyzed based on their amino acid composition and secondary structure of the polypeptides. This review provides a theoretical basis for the production of walnut-derived antioxidant peptides and could help promote the development of the walnut industry.

Antioxidant peptides derived from woody oil resource by-products exhibit strong free radical scavenging abilities and offer potential applications in functional foods, nutraceuticals, and cosmetics. This review summarizes the latest advances in preparation technologies, including enzymatic hydrolysis, microbial fermentation, chemical synthesis, recombinant expression, and molecular imprinting, each with distinct advantages in yield, selectivity, and scalability. The structure–activity relationships of antioxidant peptides are explored with respect to amino acid composition, molecular weight, and 3D conformation, which collectively determine their bioactivity and stability. Additionally, emerging delivery systems—such as nanoliposomes, microencapsulation, and cell-penetrating peptides—are discussed for their role in enhancing peptide stability, absorption, and targeted release. Mechanistic studies reveal that antioxidant peptides from woody oil resources act through network pharmacology, engaging core signaling pathways, including Nrf2/ARE, PI3K/Akt, AMPK, and JAK/STAT, to regulate oxidative stress, mitochondrial health, and inflammation. Preliminary safety data from in vitro, animal, and early clinical studies suggest low toxicity and favorable tolerability. The integration of omics technologies, molecular docking, and bioinformatics is accelerating the mechanism-driven design and functional validation of peptides. In conclusion, antioxidant peptides derived from woody oil resources represent a sustainable, multifunctional, and scalable solution for improving human health and promoting a circular bioeconomy. Future research should focus on structural optimization, delivery enhancement, and clinical validation to facilitate their industrial translation.

Camellia seed oil (CSO) is rich in unsaturated fatty acids; however, its application is limited by its susceptibility to oxidation. In this study, camellia seed oil was encapsulated in a pea peptide - maltodextrin (PP/MD) matrix by spray drying to form microcapsules (CSOM). The CSOM exhibited a mean particle size of 511 nm, high encapsulation efficiency, and good colloidal stability. In vitro digestion showed that CSOM exhibited a progressive release profile, with limited release during the oral and gastric phases and increased release during intestinal digestion. In H₂O₂-induced PC12 cells, CSOM significantly reduced ROS accumulation, enhanced antioxidant enzyme activity, and improved cell viability compared with free CSO. Transcriptomic, RT-qPCR, and protein expression analyses indicated that the cytoprotective effects of CSOM were associated with modulation of PI3K/Akt-related signaling and apoptosis-related proteins. Overall, PP/MD microencapsulation improved CSO stability, modulated simulated gastrointestinal release, and enhanced cellular protection against oxidative stress.