Bioaccessibility Performance of Phenolic Compounds from Red Fruits During Simulated Gastrointestinal Digestion and Colonic Fermentation

Red fruits are rich in phenolic compounds, particularly anthocyanins, which contribute to their vibrant colors and health benefits. However, anthocyanins are chemically sensitive during digestion, which affects their bioaccessibility. This study evaluated the impact of simulated gastrointestinal digestion on whole red fruits (oral, gastric, intestinal, and colonic phases). Total phenolic content (TPC) ranged from 8.60–50.41 mg GAE/g DW, total flavonoid content (TFC) from 1.66–10.67 mg CAT/g DW, and total monomeric anthocyanins (TMA) from 0.54–1.28 mg CYA/g DW. Antioxidant activity strongly correlated with TPC (r ≥ 0.91). High-phenolic fruits showed lower bioaccessibility compared with low-phenolic ones. HPLC-DAD-ESI/MSⁿ identified glycosylated anthocyanins, which were highly sensitive; jaboticaba anthocyanins were nonbioaccessible, while 51.83% remained bioaccessible in raspberries. Colonic fermentation further reduced TPC and TFC, and anthocyanins were entirely degraded. These results highlight the need for innovative delivery systems to improve anthocyanin bioaccessibility and functional benefits.