Potential of drying carrot using ozone pre-treatment: Mass transfer modelling and techno-functional properties

The objective of this study was to investigate the influence of ozone (O3) as a novel pre-treatment for carrot drying. To establish the best conditions, carrot cubes were exposed to increasing concentrations of O3 (0-40 mu g/ L) for 2 h before air convective drying at 70 degrees C. According to the mass transfer models, the results highlighted a correlation between higher effective diffusivity (4.654 x 10-11 m2/s) and increasing O3 concentrations. Furthermore, dried carrot cubes exhibited sustained levels of phenolic compounds (29.33-56.42 mg GAE/100 g), carotenoids (5.17-14.58 mg/100 g), antioxidant activity (1.27-5.01 mu M Trolox/g), and inhibitory activity (IC50) against alpha-amylase (56.02-95.63 mu g/mL) and alpha-glucosidase (29.72-69.08 mu g/mL) as the O3 concentration increased up to 40 mu g/L. Differential scanning calorimetry analysis showed different thermal profiles on carrot cubes due to O3 treatment. Furthermore, the O3 pre-treatment significantly accelerated and enhanced the rehydration of carrot cubes, resulting in faster absorption of moisture and restoration to the initial texture and volume. Overall, this study shows that O3 pre-treatment (40 mu g/L) can be a rational strategy to optimize drying