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 ( R 2 = 0.9965−0.9996). Higher temperatures increased drying rates (3.7 × 10 −3 to 1.2 × 10 −2 kg H 2 O kg −1 db min −1 ) and moisture diffusivity (4.00 × 10 −8 to 2.17 × 10 −7 m 2 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 CO 2 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. • Higher temperatures enhance the drying efficiency of blueberry pomace. • Page model best predicts drying; activation energy of 39.55 kJ mol −1 . • Above 70 °C, soluble fiber increases while insoluble decreases. • Techno-functional properties are modified by increasing temperatures. • Bioactive compounds and antioxidant activity increase with higher temperatures.