Optimization of osmotic dehydration process for Oyster mushrooms (Pleurotus sajor-caju) in sodium chloride solution using RSM

Abstract

Sodium chloride (NaCl) and water transfer were quantitatively investigated during osmotic dehydration of Oyster mushrooms (Pleurotus sajor-caju) using response surface methodology with the NaCl concentration (10– 20%, w/v), solution temperature (30–60° C) immersio n time (15–240 min) and solution to fruit ratio (4:1 to 8:1) were taken as independent process variables. Experiments were conducted in a thermostatically controlled agitating incubator. For each response, second order polynomial models were developed using multiple linear regression analysis. Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The response surfaces and contour maps showing the interaction of process variables were constructed. Applying desirability function method, the optimum operating conditions were found to be: solution temperature – 45o C, immersion time – 53.54 min, salt concentration – 14.09% and solution to fruit ratio 6.08:1. Corresponding to these optimum values water loss, solute gain and weight reduction were 38.13, 2.1 and 36.02 (g/100 g initial mass) respectively.