Characterization of volatile organic compounds in Polygonum multiflorum and two of its processed products based on multivariate statistical analysis for processing technology monitoring

•HS-SPME-GC-MS and HS-GC-IMS were combined to provide an in-depth detection of VOCs in raw PM and two of its processed products.•The overall difference of raw PM and two of its processed products was observed by PCA of VOCs from HS-SPME-GC-MS and fingerprint of VOCs from HS-GC-IMS.•Cluster-KDE smoothly and hierarchically determined the content and distribution of VOCs in the samples based on the cluster density plots.•The significant markers for identifying PM processing technology were screened by EFA.