Résumé
This study aims to construct a dynamic two-dimensional characterization technique for the hygroscopicity of traditional Chinese medicine extracts and investigate the effect of material properties of powders on hygroscopicity. The dynamic hygroscopicity-time curves of the powders were measured at 25 ℃ and 75% humidity, and the semi-equilibrium hygroscopicity time (t1/2) and equilibrium hygroscopicity (F∞) were derived as two-dimensional evaluation indicators. Finally, the correlation between the material properties and the hygroscopic behavior was analyzed by principal component analysis (PCA) and partial least squares analysis (PLS). The results showed that the dynamic two-dimensional characterization system of hygroscopicity constructed with 1/t1/2 = 0.1 h-1 and F∞ = 15% as the center can classify the hygroscopic behavior of traditional Chinese medicine extracts into four categories: fast hygroscopicity with strong hygroscopicity, slow hygroscopicity with strong hygroscopicity, fast hygroscopicity with weak hygroscopicity and slow hygroscopicity with weak hygroscopicity. The moisture absorption was negatively correlated with D50, D90, ρb and ρt; the moisture absorption rate was negatively correlated with D10, D50, D90, ρb, ρt, and positively correlated with moisture content. The hygroscopicity dynamic two-dimensional characterization indicators of Chinese medicine extracts (CMEs) constructed in this study matched with the physical properties. The method of dynamic multi-dimensional characterization technology is feasible and scientific, and the idea has strong promotional value.