Drying characteristics,drying kinetics and product quality of Flos lonicerae during infrared-forced air drying

Objective: To study the infrared- forced air drying characteristics and drying kinetics mathematical model of Flos lonicerae.Methods: The experiment was carried out at different infrared radiation drying temperatures( 35,45,55 ℃).The drying characteristics were detected and the drying kinetics mathematical model was established.Meanwhile,the value of colour and effective constituents were detected. Results: The drying time decreased with the increase of the drying temperature.According to statistical parameters,the Page model predicts and describes the drying process more accurately than others. There was a good agreement between the experimental and predicted values.Since the drying process occurred in falling rate periods,the Fick's second law of diffusion was employed to calculate the value of moisture effective diffusivity( Deff),which ranged from 5.06606 × 10- 9~7.59909 ×10- 8m2/ s,and increased with the increasing of drying temperature. The value of ΔE was least and the effective constituent was maximum at 35 ℃ of Flos lonicerae.The activation energy determined from Arrhenius equation was113.569 k J / mol. Conclusion: The drying process of Flos lonicerae only contained deceleration stage.The Page model was the best suitable for predicting moisture ratio.The infrared drying at 35 ℃ compared with drying in the shade was more efficient.