Far-infrared drying characteristics and quality assessment of Ligularia fischeri

Abstract

The purpose of this study was to investigate drying models and drying characteristics of Ligularia fischeri by using far-infrared drying. The far-infrared drying tests on L. fischeri were performed at air velocities of 0.6 and 0.8 m/s, and drying chamber temperatures of 40, 45, and 50°C. Four thin layer drying models were used to estimate drying curves. Drying characteristics were analyzed on the basis of drying rate, color, antioxidant activity, and contents of polyphenolics and flavonoids. The goodness of the models was estimated using the coefficient of determination, the root mean square error, and the reduced chi-square. The results revealed that increases in drying temperature and air velocity caused a decrease in drying time. The Page and Thompson models were considered suitable for the far-infrared drying of L. fischeri. After drying, the antioxidant properties of L. fischeri were decreased under all drying conditions.