Effects of Enzyme- and Ultrasound-Assisted Treatments on the Recovery of Insoluble-Bound Phenolic Antioxidants from Common Bean Flours

Common beans contain insoluble-bound phenolic compounds with potential bioactive properties; however, their recovery generally depends on harsh hydrolytic conditions and organic solvents. This study evaluated alternative extraction strategies for the recovery of insoluble-bound phenolic compounds from raw and cooked common bean flours of two Andean varieties (Peumo and Magnum), using Viscozyme L®, ultrasound, and pretreatment with ultrasound followed by Viscozyme L®. The resulting extracts were characterized in terms of phenolic profile by UPLC-ESI-MS/MS, total phenolic content (TPC), and antioxidant activity. Enzymatic treatment improved the recovery of insoluble-bound phenolic compounds and antioxidant activity compared with the control, while ultrasound alone showed limited effectiveness under the evaluated conditions. The combination of ultrasound pretreatment and Viscozyme L® generally improved recovery of some phenolic compounds and antioxidant-related endpoints relative to control conditions. Cooking generally reduced TPC and antioxidant activity, although the effect on individual phenolic compounds depended on the extraction treatment. Overall, enzyme-assisted extraction, especially when combined with ultrasonic pretreatment, represents a promising strategy for improving the recovery of insoluble phenolic compounds from common bean flour. Further optimization is still needed to improve the sustainability of the process and its industrial applicability.