In this study, we analyzed the composition and content of 25 free amino acids in 32 batches of different forms of Cervi Cornu Pantotrichum(CCP; one-branched, two-branched, and three-branched) from 15 producing areas. The clustering analysis and orthogonal partial least squares discriminant analysis(OPLS-DA) were performed based on the content of 25 free amino acids. Potential differential metabolites were identified based on VIP value. The results showed that there were 25 free amino acids in CCP, and the average content of essential, non-essential, and total amino acids was 6.13, 32.99, and 39.12 mg·g~(-1), respectively. The clustering analysis and OPLS-DA demonstrated that 25 free amino acids had different content among the three forms of CCP, of which two-branched CCP samples were separately gathered into a group. Five differential components, including glutamic acid, tryptophan, ornithine, γ-aminobutyric acid, and hydroxylysine, were screened out as potential quality markers for the identification of different forms of CCP. This study provides a theoretical basis for the quality evaluation, processing, and utilization of different forms of CCP.
Keywords: Cervi Cornu Pantotrichum; different forms; free amino acid; orthogonal partial least squares discriminant analysis; quality control.