Abstract

Shrinkage is an important factor affecting the final quality of Radix Paeoniae Alba (RPA) slices during drying processes. In this study, drying experiments were carried out to determine the effect of the initial drying of roots on RPA slice shrinkage. The RPA root was initially dried to an initial moisture content (M₀) and then cut to slices that were sequentially dried to the targeted final moisture content to decrease the shrinkage symptoms of RPA slices. In this approach, M₀ should be high enough to easily slice the roots without being cracked and as low as possible to decrease the deformation of the slices during the final drying. Results showed that the shrinkage ratio of the RPA slices decreased with the decrement of M₀ and the increment of drying temperature (T). At a high T (70 °C), high M₀ (up to 0.45 d.b.) could be effectively used to slice and dry RPA roots with less shrinkage in the final product, whereas at a low T (50 °C), low M₀ (≤ 0.35 d.b.) should be used. A 3D model with moving boundary was also developed to simulate the drying and shrinkage process of RPA slices. Simulation results showed that the model successfully predicted the moisture content and temperature of RPA slices and simulated their shrinkage behavior during drying, with reasonable accuracy.

摘要

在干燥过程中，收缩率是影响白芍（RPA）切片最终质量的重要因素。在这项研究中，进行了干燥实验，以确定根的初始干燥对 RPA 切片收缩的影响。RPA 根部最初干燥至初始水分含量 ( M ₀ )，然后切成薄片，依次干燥至目标最终水分含量，以减少 RPA 切片的收缩症状。在这种方法中，M ₀应该足够高，以便在不开裂的情况下轻松切片根部，并尽可能低以减少最终干燥过程中切片的变形。结果表明，RPA切片的收缩率随着厚度的减小而减小。M ₀和干燥温度增量（T）。在高T (70 °C) 下，高M ₀ (高达 0.45 db) 可以有效地用于切片和干燥 RPA 根部，最终产品的收缩较小，而在低T (50 °C) 下，低M应使用_{0 (≤ 0.35 分贝)。}还开发了具有移动边界的 3D 模型来模拟 RPA 切片的干燥和收缩过程。仿真结果表明，该模型成功地预测了RPA切片的水分含量和温度，并模拟了其干燥过程中的收缩行为，具有合理的准确性。