Optimization of Osmotic Dehydration Process of Aonla Fruit in Salt Solution

For optimization of osmotic dehydration process of aonla fruit in salt solution by response surface methodology, the experiments were conducted according to Box and Behnken design. The independent process variables for osmotic dehydration process were osmotic solution concentrations (5-25% w/v salt), osmotic solution temperature (30-60 degrees C), solution to fruit ratio (4-8 v/w), and process time (60-240 minutes). The osmotic drying process was optimized for maximum water loss, overall acceptability and minimum solute gain, colour change, and vitamin-C loss. The optimum conditions were 22% salt concentration, 44.5 degrees C osmotic solution temperature, 6.5 solution to fruit ratio, and 60 minutes process time. An analysis of variance (ANOVA) revealed that, among the process variable, concentration has the most significant effect on water loss, solute gain, and overall acceptability; solution temperature has the most effect on colour change; and process time has the most effect on vitamin-C loss whereas solution-to-fruit ratio observed significantly lower effect on responses.