Influence of osmotic dehydration process parameters on the quality of star fruit (Averrhoa carambola L.)
The study of the kinetics of osmotic dehydration of star fruit is important in the production of high quality candied fruit. The mass transfer kinetics during the dehydration process was modeled assuming a Fickian diffusion of sucrose and water under static conditions. For the study we used three osmotic solutions with sucrose concentrations of 40, 50 and 60 ° Brix and determined the effect on solid gain and water loss. The kinetic data were modeled using equations Azuara, Magee and Peleg and effective diffusivity was calculated using the Crank model. Additionally, we studied the effect of osmotic dehydration process on the physicochemical and sensory quality of osmotically dehydrated fruits. The results showed that the largest loss of water was given at the concentration of 60 ° Brix, and the solid gain was greater in 50 ° Brix. Magee models and Azuara were the most suitable for the fit of the experimental data by high R2 values (> 0.90), and the effective diffusivity was 9,79838x10-10, 1,06444x10-09, 7,94466x10-10 for water loss and solid gain 1,13954x10-09, 1,20477x10-09, 1,06047x10-09 for concentrations of 40, 50 and 60 ° Brix respectively. The firmness, acidity, soluble solids and moisture were significantly affected by the concentration of osmotic solutions (p <0.05), meanwhile the pH and color parameters were not affected. Regarding sensory evaluation was found that osmotically dehydrated fruits at 50 °Brix had the highest sensory acceptability by a consumer panel.