Effect of Microwave and Hot Air Drying on the Physicochemical Characteristics and Quality of Jelly Palm Pulp

Abstract

The drying of jelly palm pulp with hot air (HA) or microwave (MW) radiation was evaluated at three temperatures (50, 60 and 70°C), and the physicochemical and sensory properties of the dried pulp were considered. Drying using MW increased the drying rate and a reduction in the drying time compared with HA. Infrared thermography showed heterogeneous heating using MW. The water activity of the dried pulp ranged from 0.43 to 0.51. The colour of the dried pulps at 50 and 60°C after using both techniques suffered less thermal degradation than drying at 70°C, which generated darker pulp. The best results were obtained using MW at 60°C, because this presented no significant sensory differences and required a shorter drying time than MW at 50°C.