Kinetics of mass transfer, and colour changes during osmotic dehydration of watermelon Original Research Article

Mass transfer during osmotic dehydration of watermelon, and colour changes of fresh, osmosed and osmo-oven dried watermelon were investigated. Mass transfer during osmotic dehydration was modeled using Fick’s second law of diffusion. CIE colour parameters (L∗a∗b∗) of fresh, osmosed, and osmo-oven dried watermelon were measured and, colour intensity, chroma and hue angle were calculated. Moisture and solid diffusivities were in the range of 1.030× 10−8–3.549×10−9 m2/s and 1.117 × 10−8–8.540 × 10−9 m2/s, respectively. Activation energy for moisture and solids diffusivity ranged from 5.09 to 32.77 kJ/mol and 3.43 to 32.38 kJ/mol, respectively. Generally, L∗, a∗, b∗, colour intensity and chroma values increased with increase in osmotic solution concentration in osmosed and osmo-oven dried watermelon.