Statistical Optimization of Process Variables for Osmotic Dehydration of Okra (Abelmoschus esculentus) in Sucrose Solution
The objective of this study was designed to elucidate the effects of temperature, solute concentration, and size diameter and process time on the osmotic dehydration of okras in sucrose solution. Response Surface Methodology (RSM) with Central Composite Rotable Design (CCRD) was used with five levels and four factors (temperature, sucrose concentration, size diameter and process time) as independent variables, while water loss and solute gain as dependent (response) variables. The osmotic dehydration data was well fitted to a second-order quadratic polynomial regression model with high correlation coecient (R2 > 0.90) using the Statistica program (v. 6.08). The quadratic regression models for the water loss and solute gain yielded signicant (p < 0:05) and predictive results. The osmotic dehydration process was optimized for water loss and solutes gain. The predicted optimum conditions to achieve 39. 78 percent water loss and 10.16 percent solute gain were found to be: solute concentration, 49.28(% w/w); solution temperature, 40.79; sam- ple size diameter, 15mm and process time, 4.49hr. At this predicted optimum point, the observed water loss and solute gain were found to be 38.87 and 10.65(g/100g initial sample), respectively.
Keywords: okra, optimization, osmotic dehydration, process variables, response surface, sucrose