Simulated Digestion and Bioaccessibility of Cookies Enriched with Microencapsulated Polyphenols from Habanero Pepper Leaves Extracted Using NADES

This study presents the formulation of a cookie enriched with microencapsulated polyphenols from Capsicum chinense (Habanero pepper) leaves, extracted using a green ultrasound-assisted Natural Deep Eutectic Solvent (NADES) of choline chloride and glucose (1 : 0.8 mol/mol) with 68% water. For microencapsulation, the extract was spray-dried with maltodextrin, modified starch, and guar gum, and the powder with the highest Total Polyphenol Content (TPC) was used to replace 20% (w/w) of common wheat flour. Digestion was simulated under fasted and postprandial conditions across gastric and intestinal phases. The enriched cookie showed a maximum TPC release of 273.6 ± 12.2 mg Gallic Acid Equivalent (GAE)/100 g at the intermediate intestinal stage (fasted), and antioxidant capacity peaked at 84.4 ± 1.5% inhibition in the final intestinal phase (postprandial). High-Performance Liquid Chromatography (HPLC)-Diode-Array Detector (DAD) identified protocatechuic acid (3.86 ± 0.23 mg/100 g), catechin (6.99 ± 0.42 mg/100 g), and rutin (1.79 ± 0.06 mg/100 g) in the undigested cookie. After digestion, their concentrations increased at the intestinal stage (fasted): protocatechuic acid by 101.3%, catechin by 828.76%, and rutin by 1,481.82%. Statistical analysis (p < 0.05) showed significant effects of cookie type, digestion condition, phase, time, and their interactions. These findings support NADES-based microencapsulation as a promising strategy for enhancing polyphenol bioaccessibility in functional bakery products.