Bioaccessibility Evaluation by In Vitro Digestion of Microencapsulated Extracts of Habanero Pepper Leaves Obtained Through an Optimized Spray-Drying Process

Habanero pepper (Capsicum chinense Jacq.) leaves, a major by-product of pepper cultivation in the Yucatán Peninsula, are an underexploited source of phenolic compounds with relevant antioxidant potential. In this work, phenolic-rich extracts obtained with a choline chloride–glucose Natural Deep Eutectic Solvent (NADES) and ultrasound-assisted extraction were microencapsulated by spray-drying using maltodextrin and Guar gum. The microcapsules were analyzed using Raman spectroscopy, total polyphenol content (TPC), and antioxidant capacity (Ax), and were subsequently subjected to in vitro gastrointestinal digestion to assess their bioaccessibility. Raman spectra confirmed the formation of a maltodextrin–Guar-gum matrix with broad glycosidic bands (480–1450 cm−1) and CH-stretching at ≈2900 cm−1, indicative of polymer–phenolic interactions. From de experimental design, the formulation containing 5% Guar gum at 100 °C reached the highest intestinal TPC (31.00 ± 0.30 mg GAE/100 g powder) and increased TPC bioaccessibility at the intestinal phase (283.28 ± 3.22%), evidencing efficient enzymatic release of bound phenolics. The greatest pre-digestion antioxidant capacity (19.56 ± 0.33% DPPH inhibition) corresponded to 7.5% GG at 104 °C, while intestinal antioxidant recovery peaked at 17.34 ± 0.14% (7.8% GG, 89.4 °C). The optimal TPC bioaccessibility value obtained was 358.3%, under optimal spray-drying conditions, consisting of 4% guar gum and an inlet temperature of 104 °C. Overall, the synergy between NADES-based extraction and optimized spray-drying enabled a stable, digestion-responsive encapsulation system that substantially enhanced phenolic retention and intestinal bioaccessibility, supporting its application as a sustainable strategy to valorize C. chinense leaves into antioxidant-rich functional ingredients.