Chitosan Aerogels Loaded with Black Bean Peptides and Phenolics Modulate Oxidative and Inflammatory Markers after Microbial Fermentation In Vitro

Abstract

The nondigestible fraction of food-grade bioactive carriers loaded with bioactive compounds may reach the colon and become available for microbial fermentation. This in vitro study assessed the gastrointestinal bioaccessibility and antioxidant and anti-inflammatory potential of peptide-functionalized chitosan aerogels impregnated with an anthocyanin-rich extract (ARE). Chitosan-based aerogels (Aero-Q) were functionalized with black bean protein hydrolysates (Aero-P), and Aero-P was also impregnated with ARE (Aero-A) through wet impregnation. Aerogels achieve high impregnation efficiencies of total anthocyanins (83.4–99.1%) and total phenolics (41.9–87.5%). Simulated gastrointestinal digestion revealed that anthocyanins showed low colonic bioaccessibility (0.05%). However, microbial fermentation of the nondigestible fraction of functionalized chitosan aerogels significantly elicited an anti-inflammatory response in RAW 264.7 macrophages, by reducing intracellular reactive oxygen species (62.0–105.1%), nitric oxide levels (17.3–59.1%), and TNF-α, COX-2, and iNOS expression. Peptide-functionalized chitosan aerogels could preserve black bean bioactives within the nondigestible fraction, allowing fermentation-derived products to modulate oxidative and inflammatory markers in vitro.