The Effect of Temperature on Drying Kinetics and Beta-Carotene Content of Carrot Pomace Using Convective Hot Air Dryer

The use of agricultural waste is always important; one of the most important processes for increasing their shelf-life is drying. The purpose of this study was to investigate the drying kinetics of carrot pomace and evaluating the antioxidant and color properties of it. For this purpose, the prepared pomace was dried at 50, 60 and 70 °C, and the antioxidant and colorant properties of fresh and dried pomace were studied. The results showed that the best model for predicting drying kinetics of carrot pomace was Midilli-Kucuk model with correlation coefficient (R2) of 0.9994, 0.9994 and 0.9986 and root mean square error (RMSE) 0.0088, 0.0091 and 0.019 for the temperatures of 50, 60 and 70 oC, respectively. During the drying process, the amount of carrot pulps beta-carotene (30.10 ±0.08 at 60 °C) 80.2% was reduced compared to fresh pomace (150.66 ± 1.4 mg/100g), this difference was significant (p<0.005). Also, the temperature of 60 °C had the greatest effect on the reduction of beta-carotene. Reducing the amount of beta-carotene led to the color indicators alterations. An indicator changes showed a high correlation (0.988) with beta-carotene content.