Modified starches from bananas offer an opportunity to encapsulate underutilized South American fruits to deliver antioxidant compounds such as polyphenols. This research aimed to evaluate the bioaccessibility and intestinal permeability of polyphenols from Andean blackberry (Rubus glaucus Benth) powder encapsulated in octenyl succinic anhydride (OSA)-modified Gros Michel banana starch. For this, OSA-modified Gros Michel banana and blackberry powder capsules were produced using an optimized spray-drying procedure. Then, an in vitro gastrointestinal digestion simulating the oral, gastric, and intestinal stages was conducted, and the bioaccessibility of total phenolics, total flavonoids, and condensed tannins was quantified using spectrophotometric analysis. Moreover, specific polyphenols were quantified along with the digestion by HPLC-DAD. The simulated gastrointestinal digestion showed a low bioaccessibility of total phenolics, flavonoids, and condensed tannins (up to 6 %), but gallic and chlorogenic acids and quercetin were the most bioaccessible quantified polyphenols. High apparent permeability values were obtained for total phenolics (5-22 × 10-6 cm/s), which could be explained by the in silico simulations between the primary identified polyphenols and a model of intestinal membrane, where (+)-catechin displayed the highest binding affinity (-8.50 kcal/mol). This research encourages research using novel starch sources for encapsulating functional fruits to validate their potential health benefits through gastrointestinal digestion.