Osmotic dehydration behavior of red paprika (Capsicum annuum L.)

Osmotic dehydration of red paprika was studied using a combined sucrose (5 to 45 g/100 g) and sodium chloride (0 to 15 g/100g) solution. The effective diffusion coefficients for water and solute were determined using the slope method based on the Fickian diffusion model. The effects of concentration of sucrose, sodium chloride and their complex interaction on water and solute diffusion coefficients as well as on equilibrium moisture and solid contents were studied using central composite rotatable design of experiments. The graphical optimization showed that at optimum conditions (sucrose concentration and sodium chloride concentration were 21.86 g/100 g and 2.02 g/100 g, respectively), the following criteria were achieved: water diffusion coefficient (Dew) ≥ 0.80 × 10-9 m2/s, solid diffusion coefficient (Des) ≥ 0.82 × 10-9 m2/s, equilibrium moisture content (m∞) ≤ 6.85 kg/kg, and equilibrium solid content (s∞) ≤ 2.00 kg/kg.