Food Structure Modulation of Antioxidant Bioaccessibility and Gut Epithelial Protection: The Case of Bread and Pasta Made With Pigmented Wheat

Food structure is expected to play an important role in modulating nutrient bioavailability and antioxidant activity in cereal-based foods. This study examined how semolina type [pigmented grains (Grano Mischio, GM) vs. traditional wheat (Senatore Cappelli, SC)] and the food matrix (bread vs. pasta) influence product quality, in vitro starch digestibility, antioxidant capacity, and intestinal barrier integrity of Caco-2 cells. GM-bread had lower specific volume and was harder than SC-bread, while GM-pasta showed significantly higher starch digestibility compared to SC-pasta, probably due to polyphenol-induced structure weakening. Antioxidant activity, measured by ORAC, DPPH, and ABTS assays, varied by matrix and method, with GM-pasta exhibiting higher radical scavenging capacity than GM-bread in the DPPH and ABTS assays. Caco-2 cells treated with digested GM-pasta showed increased viability, enhanced transepithelial electrical resistance, and reduced inflammatory markers (IL-1β, IL-11, NF-κB) under pro-inflammatory conditions. Overall, pigmented wheat products, particularly pasta, retain antioxidant properties upon digestion. These findings provide evidence that food processing can modulate the biological properties of raw cereal materials, laying a promising foundation for the rational design of functional foods that leverage matrix architecture to optimize the release and efficacy of bioactive compounds during digestion.