Optimization of factors influencing osmotic dehydration of aonla (Phyllanthus emblica L.) segments in salt solution using response surface methodology

Optimization of process parameters is a critical requirement in food processing and food product industries for the development of highly acceptable product. Quantification of mass transfer kinetics under different processing conditions is essential step for optimizing the osmotic dehydration process. A Box-Behnken Design (BBD), adopted from response surface methodology (RSM) approach was used for evaluating and quantifying the moisture loss and solids gain kinetics of aonla segments in salt solution during the osmotic dehydration process. The independent variables were fixed at three levels (salt concentration- 2, 4, 6%; processtemperature - 45, 50, 55 OC and process time - 60, 120, 180 minutes). The process responses were water loss percentage (WL%) and solids gain percentage (SG%). Validation experiments were conducted at optimum conditions to verify predictions and adequacy of the models. The optimum conditions predicted were 5.02% salt concentration, 54.8 OC temperature and 60.64 minutes process time to attain a desired effect of maximum water loss (6.42%) and minimum solid gain (1.09%) in osmotic dehydration of aonla in salt medium.