Chemometric discrimination of geographical variations in Litsea cubeba essential oils based on their chemical compositions and antioxidant activities

• Litsea cubeba essential oil (LcEO) exhibits geographical variation in the composition. • The antioxidant activity of LcEOs varies depending on their chemical composition. • β-citral, geraniol and D-limonene may suppress the antioxidant activity of LcEO. • Linalool, citronellal and six other components synergize the antioxidant activity. The Litsea cubeba essential oil (LcEO) gains increasing attention as an important natural spice for food, flavor and fragrance industries. The chemical composition of LcEO determines its bioactivity and varies from provenance to provenance of the plant. This study investigated the geographic variation of LcEOs based on their compositions and antioxidant activities to differentiate their geographic origins. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) categorized nine provenances across South China and Southeast Asia into four chemometric groups based on the chemical composition LcEO samples, where 63 compounds were identified, mainly including α-citral (34.53-41.92%), β-citral (25.93-38.85%), and D-limonene (8.93-24.7%). Furthermore, PCA and orthogonal partial least square discriminant analysis (OPLS-DA) clustered these nine provenances into RG (relatively good) and RP (relatively poor) groups based on LcEO’s antioxidant activities, where OPLS-DA demonstrated the relationship between antioxidant activity and chemical composition. Eleven components were selected as key contributors to the grouping, where β-citral, geraniol and D-limonene were negative contributors whereas eight other components like linalool and citronellal were positive contributors based on their correlation coefficients. Our chemometric discrimination could help trace the provenance of LcEO products and guide the precise screening of wild L. cubeba varieties according to LcEO’s composition.