Natural Ingredients to Enhance the Antioxidant Capacity in Different Meat Products: A Review

The oxidative stability of meat products is a crucial factor determining quality, shelf life, and consumer acceptance, as lipid and protein oxidation promote undesirable changes in sensory attributes and nutritional content. Antioxidant capacity (AOC) assays such as total phenolic content (TPC), ferric reducing antioxidant power (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), and 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) are commonly applied in meat systems to assess the AOC associated with both intrinsic muscle components (endogenous) and the protective effects of natural ingredients (exogenous added compounds), i.e., antioxidants. Although differences in analytical methodologies limit direct comparisons among studies, it has been demonstrated that meat products inherently contain compounds that modulate oxidative reactions, with their effectiveness influenced by meat type, processing, and storage conditions. Within this framework, natural ingredients, including plant- and fungal-derived ingredients and their by-products, have gained attention as sources of natural antioxidants, whose capacity depends on the extraction method, the solvent used, and their behavior during gastrointestinal digestion, as evaluated using simulated gastrointestinal digestion (sGD) models. Numerous studies have shown that incorporating natural extracts or powders into meat products enhances AOC during refrigerated storage, with the effect generally depending on the concentration used. Moreover, several natural antioxidant treatments maintain or even enhance their AOC when assessed under sGD conditions.