Investigation of the effect of ultrasound pretreatment on shrinkage of cornelian cherry during hot air drying

In this study, the effect of ultrasound pretreatment, air velocity and temperature on cornelian cherry shrinkage during hot air drying process were investigated. Ultrasound pretreatment at two time levels (10 and 30 minutes) was applied and then the samples were dried at 40, 50 and 60°C and 1, 1.5 and 2 m/s air velocity. Afterwards, shrinkage data were fitted to three experimental models. The results showed that with decreasing moisture content during drying, the thickness of the samples reduced from 0.0138 to 0.0078 m. The application of ultrasound pretreatment led to a significant (P<0.05) decrease in thickness. Moreover, one of the models was selected as the best suitable model in predicting thickness changes of cornelian cherry (R2=0.99) under the experimental conditions. Through multiple regression analysis, the relations between the coefficients of the models with the variables used were obtained.