Impact of the Bean Protein Concentrate and Maltodextrin Mixture as an Alternative Wall Material in the Microencapsulation of Gallic Acid: Physicochemical, Techno-Functional, Antioxidant Characterization and Optimization

This study evaluated the use of Michigan bean protein concentrate (PC) and maltodextrin (MD) as alternative wall materials for the microencapsulation of gallic acid, selected as a model phenolic compound due to its well-defined structure and suitability for assessing encapsulation efficiency, stability, and matrix–polyphenol interactions. Increasing the inlet temperature enhanced microencapsulation yield (37.25–55.56%) and total color difference (5.23–13.20), but reduced DPPH• radical inhibition from 90.92% to 54.04%, ABTS•+ radical inhibition from 99.43% to 79.98%, moisture content from 4.98% to 3.51%, and water activity from 0.35 to 0.30. Higher PC concentrations increased efficiency (86.45–99.26%), microencapsulation retention (38.06–100%), moisture content (3.51–4.98%), Aw (0.301–0.358), water absorption capacity (0–2.38 g/g), oil absorption capacity (3.31–3.67 g/g), and emulsifying capacity (0–2.2%). The interaction between temperature and PC content significantly improved yield, antioxidant capacity, and moisture content. Optimal conditions were achieved at a PC:MD ratio of 51:49 and a temperature of 116 °C. Under these conditions, yield, efficiency, microencapsulation retention, total phenolic content, and DPPH• radical inhibition were higher than the values predicted by the model. Morphological analysis revealed that the microcapsules exhibited irregular shapes with dents and particle sizes ranging from 5.43 to 10.19 µm. These findings demonstrate that Michigan bean protein concentrate, when combined with maltodextrin, exhibits strong potential as a wall material for gallic acid microencapsulation, achieving high retention and microencapsulation efficiency.