A comprehensive study of the effect of drying methods on compounds in Elaeagnus angustifolia L. flower by GC-MS and UHPLC-HRMS based untargeted metabolomics combined with chemometrics

The effect of drying methods on the variations of volatile, semi-volatile, and involatile compounds in Elaeagnus angustifolia L. (E.A.) flower was comprehensively investigated by using gas chromatography-mass spectrometry (GC-MS) and ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) based untargeted metabolomics combined with our recently developed automatic data analysis software AntDAS for the first time. About 21 volatile compounds, 44 semi-volatile compounds, and 17 involatile compounds were identified and showed significant differences among drying methods. Chemometric methods like principal components analysis (PCA), and partial least squares-discriminant analysis (PLS-DA) were used in combination with heatmap analysis to reveal the relationship between compound compositions and drying methods. Finally, it was concluded that room-temperature drying is more conducive to preserving volatile compounds in E.A. flower, and hot air drying is better for preserving semi-volatile and involatile compounds. This work can provide guidelines for industrial processes of E.A. flower.