Obtaining a fiber-rich ingredient from blueberry pomace through convective drying: Process modeling and its impact on techno-functional and bioactive properties

This study aimed to optimize the convective drying of blueberry pomace (BP) to enhance fiber functionality and bioactive compound retention. BP was dried at 50 90.C with an airflow of 2.5 m s 1. Drying kinetics were modeled using five mathematical models, with the Page model showing the highest accuracy (R2 = 0.9965 0.9996). Higher temperatures increased drying rates (3.7 x 10 3 to 1.2 x 10 2 kg H2O kg 1 db min 1) and moisture diffusivity (4.00 x 10 8 to 2.17 x 10 7 m2 s 1), with an activation energy of 39.55 kJ mol 1. Total dietary fiber remained stable (20.85 +/- 0.17 g 100 g 1 db), while soluble fiber increased (3.11-4.66 g 100 g 1 db) with temperature. Water- and oil-holding capacities decreased (10.86-8.61 mL g 1 db and 3.85 to 3.44 mL g 1 db, respectively). The highest total phenolic content (13.65 +/- 0.12 mg GAE g 1 db) and antioxidant activity (6.65 mg AAE g 1 db for DPPH) were observed at 70. C. Energy consumption decreased significantly (13.88-6.95 kW h 1), leading to reduced CO2 emissions. This study demonstrates the effective use of the Page model to optimize convective drying at 70.C, reducing production costs by 47% and highlighting its potential to produce fiber-rich ingredients from BP with enhanced techno-functional and bioactive properties.