Optimization of osmotic drying parameters for button mushroom (Agaricus bisporus)

Abstract

Response surface methodology was used to investigate the effect of brine concentration (10 - 20%) solution temperature (35 - 55 °C) and duration of osmosis (30 - 60 min)   with respect to water loss (WL) and salt gain (SG). The solution to sample ratio of 5/1 (w/w) was used. The Box-Behnken design of three variables and three levels including seventeen experiments formed by five central points was used for optimizing input parameters. Linear, quadratic and interaction effects of three variables were analysed with respect to water loss and solid gain. For each response, second order polynomial models were developed using multiple 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. The optimum operating conditions were: solution temperature 44.89 °C, brine concentration of 16.53% and duration of osmosis of 47.59 min. At this optimum point, water loss and salt gain were predicted to be 44.55 per cent and 2.98 per cent respectively.