中文摘要：

通过含水率试验拟合，比较了荔枝红外干燥过程各果含水率变化的均匀性，应用Image-Pro、SPSS软件，分析对比了干燥不同时刻荔枝果壳孔隙率均值差异及分形维数变化，由相对色差测定，研究了果壳表面色变过程。结果表明：荔枝红外干燥，各果含水率变化过程不均。初始质量较小果，含水率变化速率较大；随干燥时间增加，各果含水率变化速率减小，后期差距加大；干燥不同时刻果壳孔隙率随含水率降低显著性变化，其均值由0．519降至0．381、0．276、0．184，但分形维数由1．486升至1．674、1．708、1．800。荔枝红外干燥各果壳表面，初始DL、Db值变化大，后期变化小。

英文摘要：

The uniformity dynamic of moisture content of litchi fruit during infrared drying was measured and fitting analyzed. Besides, the dynamic differences of the shell porosity and its fractal dimension of litchi during infrared drying were compared using Image-Pro and SPSS software. Furthermore, the change of the color of shell surface color of litchi during fractal dimension was also measured. The results show that the moisture content change of each litchi fruit is uneven during infrared drying. For relatively small litchi, the moisture content decreases quickly during initial drying; later on, the moisture content changes slowly, and during the last drying the difference among individual drying rates becomes significant. The fruit shell porosity significantly changes with the reduction of moisture content, and its mean value decreases from 0. 519 to 0. 381, to 0. 276, and then to 0. 184; but the fractal dimension of the pore increases from 1. 486 to 1. 674, to 1. 708, and then to 1. 800. The DL and Db values of shell surface color change significantly at the beginning, however, they change slowly during the following drying. Results from this study could provide a reference for the uniformity research of other multilayer- structure fruits and vegetables in infrared drying.