بهینه سازی خشک کردن اسمز- هوای داغ گلابی با استفاده از روش سطح-پاسخ

In this study, Response Surface Methodology (RSM) was used for optimization of the conditions for hot air drying of pear slices with osmosis pretreatment. The effects of two parameters including drying temperature (50-70 °C) and drying time (240-360 minutes) as independent variables on moisture content, shrinkage percentage and rehydration ratio of pear slices as dependent variables (responses) were evaluated. The regression models for all responses were statistically significant at the 99% confidence level and lack of fit was not significant. All process variables had linear effect on all the responses (p <0.01). Also the quadratic term of drying temperature on rehydration ratio was significant. The optimum conditions obtained for minimum moisture content and shrinkage percentage and maximum rehydration ratio were: 39.60 °C as drying temperature and the drying time of 360 minutes. In optimized condition, the moisture content, rehydration ratio and shrinkage percentage of dried pear slices were 26.17%, 1.62 and 77.31 respectively.