Experimental study on spray drying of whole lotus root powder

Color retention of whole lotus root powder before spray drying was investigated. In order to achieve the color retention of whole lotus root powder before spray drying, according to the comparison of color retention results, the best parameters of color retention are that lotus slices are soaked in 0.2% citrc acid +0.1% vitamin C +0.3% sodium hexametaphate +0.2% alum or M solution for two hours. Based on single factor experiments of major parameters strongly affecting on the rate of spray drying and powder extraction, an orthogonal experiment was designed to optimize the processing conditions of spray drying of whole lotus root powder. Under the conditions of the concentration of lotus root paste 35.0%, the airflow pressure 0.25 MPa and the rotation speed of the atomizer 25000 r/min, the optimized parameters are that the feed rate of lotus root paste, the inlet air temperature and the outlet air temperature are 7.2 mL/s, 190℃ and 80 ℃, respectively.