目的 基于Dincer模型探究不同干燥方式下光皮木瓜的干燥特性，为应用Dincer模型分析中药干燥传热传质过程及筛选适宜的光皮木瓜干燥技术和工艺提供理论依据。方法 采用气体射流冲击、中短波红外和真空脉动干燥技术干燥厚度为12 mm的光皮木瓜切片，采用气体射流冲击干燥9、12、15 mm厚度的光皮木瓜切片，研究其干燥特性并测定干燥后的色泽、维生素C（VC）、总黄酮、复水比和微观结构。结果 相同干燥温度下，3种干燥技术干燥速率从大到小分别为气体射流冲击、中短波红外及真空脉动干燥技术，对应干燥活化能（E_a）为43.10、36.95、20.37 kJ/mol；减小切片厚度有助于提高干燥效率。Weibull分布函数模拟结果表明，不同干燥条件下的尺度参数α为47.85～324.51，α越小干燥时间越短，气体射流冲击和中短波红外干燥形状参数β在0.859 9～0.980 6，说明干燥为内部水分扩散控制的降速干燥过程，而真空脉动干燥条件下β介于1.218 7～1.290 8，说明干燥受内部水分扩散和表面水分蒸发所共同主导；估算水分扩散系数（D_cal）在1.66×10^-8～1.13×10^-7 m²/s，随着α值的增大而减小。Dincer模型分析干燥特性表明，不同干燥条件下滞后因子（G）为1.135 6～1.337 6，说明干燥初期均有短暂的升速干燥过程；传热毕渥数（Bi）值在1.171 4～136.041 2，且随着干燥温度的升高而减小，水分有效扩散系数（D_eff）在3.26×10^-9～6.33×10^-8 m²/s，相同干燥温度下D_eff^* < D_eff < D_cal；传质系数（k）为9.02×10^-6～8.82×10^-5 m/s，随着干燥温度的升高而增大。气体射流冲击干燥适合于光皮木瓜片的干燥加工，在实验参数范围内，干燥温度60℃、切片厚度12 mm为最优干燥工艺，干燥时间为5 h、明亮度L^*为62.80±1.70、色差值ΔE为19.62±2.60、VC和黄酮质量分数分别为（1.107 8±0.005 0）mg/g和（36.74±0.60）mg/g、复水比为7.11±0.24。结论 该研究可为应用Dincer模型在中药干燥过程分析传热传质特性及筛选适宜的光皮木瓜干燥条件提供理论依据和技术支持。

Objective Based on Dincer model, the drying characteristic of Chaenomeles sinensis under different drying condition was investigated in order to provide theoretical foundation for applying Dincer model to analyze heat and mass transfer during Chinese herbs drying process and select suitable drying technology and process. Methods C. sinensis slice of thickness 12 mm was dried by the three different drying methods, namely air impingement drying, medium and short infrared waved drying and pulsed vacuum drying. Also, 9, 12 and 15 mm C. sinensis slices were dried under air impingement drying method. The drying characteristic, color value, rehydration ration, vitamin C (VC), general flavone, and microstructure were studied. Results At the same drying temperature, the drying rate sorted in order of size was air impingement drying, medium and short infrared waved drying and pulsed vacuum drying and the drying activation energy was 43.10, 36.95 and 20.37 kJ/mol in corresponding. Decreasing slice thickness enhanced drying rate. The Weibull distribution model simulation result showed that the scale parameter α ranged from 47.85 to 324.51. Smaller α value meant short drying time. The shape parameter β was between 1.218 7 and 1.290 8 under air impingement drying as well as medium and short infrared waved drying method, which showed that drying was falling rate process controlled by internal moisture diffusion. However, the shape parameter β was between 1.218 7 and 1.290 8 under pulsed vacuum drying method, which illustrated that drying was controlled both by internal moisture diffusion and surface moisture evaporation. The calculated moisture diffusion coefficient was ranged from (1.66×10⁻⁸) to (1.13×10⁻⁷) m²/s and decreased as α increased. The Dincer model simulation result showed that the lag factor (G) was range from 1.135 6 to 1.337 6, which declared that there was a short raising rate drying period during the initial drying process. Heat transfer Biot number (Bi) value was between 1.171 4 and 136.041 2 and decreased as drying temperature increased. Effective moisture diffusion (D_eff) value calculated by Diner model was range from (3.26×10⁻⁹) to (6.33×10⁻⁸) m²/s. At the same drying temperature, (D_eff) value was larger than (D_eff^*), but smaller than (D_cal). Mass transfer (k) was ranged from (9.02×10⁻⁶) to (8.82×10⁻⁵) m/s and increased as drying temperature increased. Air impingement drying method was suitable for C. sinensis slice drying, and drying temperature of 60℃ and thickness of 12 mm was the most optimum drying process. Under above drying circumstance, the drying time, brightness L^*, color difference value ΔE, VC, general flavone and rehydration ratio were 5 h, 62.80 ±1.70, 19.62 ±2.60, (1.107 8 ±0.005 0) mg/g, (36.74 ±0.60) mg/g and 7.11 ±0.24, respectively. Conclusion Such investigation result can provide theoretical foundation for applying Dincer model to describe heat and mass transfer characteristics during Chinese herbs drying and filtrating suitable C. sinensis slice drying method and process.

R283.3

河北省自然科学基金资助项目（C2020207004）；北京市自然科学基金（6204035）；北京市教委组织部优秀人才项目（2018000020124G034）