Optimization and Evaluation of Some Physicochemical Properties of Carrot Slices Treatment in Osmosis Roselle Solution During Hot Air Drying

In this study, the changes in the color and some properties of carrot slices were investigated during hot air drying. The carrot slices first underwent an optimized osmotic pretreatment. The sucrose concentration of 60% and the dehydration time of 60 min were found to be as the optimum conditions of the osmotic dehydration. In hot air drying, temperature (60, 70 and 80°C) was taken into account as the independent variable and moisture content, shrinkage, rehydration ratio, total phenolic content, texture and sensory evaluation were considered as the dependent variables. The results revealed that the lowest reduction in total phenolic content was associated with 70°C and the effect of temperature on all of the responses was significant. With increasing temperature, shrinkage, rehydration ratio and texture increased but the moisture content decreased to (11 gr / gr). At the end, the optimum conditions were selected based on the maximum rehydration rate, phenolic compounds, total acceptance and minimum moisture content, shrinkage and stiffness of the texture were determined and the optimum temperature was 70 ° C.