Enhancement of shelf life of Coriandrum sativum leaves using vacuum drying process: Modeling and optimization

A vacuum drying process was employed to deal with the moisture removal, Vitamin C content and total dietary fiber from coriander leaves (dhania). Box–Behnken design (BBD) and response surface methodology (RSM) were applied to evaluate and optimize the three key drying parameters, namely temperature (A), loading rate (B) and vacuum (C). This approach provided statistically significant quadratic model, which was adequate to predict response and to carry out optimization under the conditions studied. It was demonstrated that the interaction between all the drying parameters has a significant effect on the moisture removal. The optimal conditions were found to be temperature of 75 °C, loading rate of 0.63 kg/m^2 and vacuum = 28 mm Hg. Under these conditions, 95% moisture removal, 527 mg/100 g Vitamin C content and 13 g/100 g total dietary fiber were obtained. Finally, product quality was also examined.