Unveiling the Effects of Drying Techniques on Phytochemical Profiles and Quality Attributes of Eriobotryae Folium

Drying is a thermodynamic process involving moisture phase transition and migration, crucial for extending the shelf life of traditional Chinese medicinal materials and reducing postharvest degradation. Eriobotryae folium (EF), the dried leaf of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae), is valued for its medicinal and functional food applications. The retention of its bioactive compounds is strongly influenced by drying methods.

In this study, the effects of shade drying, hot air-drying (50°C, 75°C, 100°C), microwave drying, and vacuum freeze-drying on the chemical composition and antioxidant activity of EF were systematically evaluated.

Using fingerprint profiling and multivariate statistical analysis, chlorogenic acid, cryptochlorogenic acid, and neochlorogenic acid (CGAs) were identified as key differential components. Spectrum-effect relationship analysis, based on Pearson product-moment correlation analysis (PPMC) and gray relational analysis (GRA), confirmed these three compounds as not only distinguishing markers under different drying conditions but also major bioactive constituents contributing to EF's therapeutic effects. Thus, they are proposed as potential quality markers. A reliable quantitative method was developed for their determination, combined with final moisture content and visual assessment of appearance, to analyze which drying method yielded samples with the best overall quality.

CGAs were confirmed as key differential components. Spectrum-effect relationship analysis confirmed these three compounds as distinguishing markers and major bioactive constituents. Microwave-dried samples exhibited the best overall quality.

This study established an integrated evaluation system-"fingerprint profiling-spectrum-effect correlation-targeted component quantification"-providing a practical and scientific approach for EF quality control and offering a reference for standardizing processing of leaf-derived herbal medicines.