Mild Temperature Conditions Applied to Carrot (Daucus carota L.) Waste Using Different Drying Methods: Effect on the Kinetics and Some Chemical Parameters
Antonio Vega‐Gálvez, Patricio Orellana‐Palma, Alexis Pastén, Elsa Uribe, Daniela Cortés, Manuel Ramón Espinosa Carvajal
Abstract
The effects of different mild drying conditions using various drying methods [freeze drying (FD), vacuum drying at 15 kPa pressure (VD15), vacuum drying at 1 kPa pressure (VD1), convective drying (CD), and infrared drying (IRD)] on drying kinetics, proximate composition, yield of extracted pectin, methoxyl content, sugar content, total carotenoids content, antioxidant potential, and color parameters of carrot wastes were examined experimentally. CD was the shortest drying treatment compared to the other drying processes, at 270 min, followed by IRD, VD1, FD, and VD15. The results showed a higher retention of pectin and carotenoids in CD-dried samples. Moreover, along with VD1, CD was able to maintain sucrose and antioxidant potential to a greater extent than other methods. Based on color parameters, FD and IRD had the most significant changes in relation to CIELab values, with ∆E* values close to 33 and 34 units, whereas VD15, VD1, and CD had values (without significant differences) close to 16, 18, and 21 units, respectively. Therefore, the current findings suggest that a short period of exposure of the waste to mild drying temperature conditions is essential for obtaining high-quality waste with potential for use in the food industry.