Volatile Components of Peel and Leaf Oils of Lemon and Lime Species

TLDR

Peel and leaf oils of 43 lemon and lime taxa were extracted and analyzed by capillary GC, GC‑MS, and 13C NMR, and the resulting data were subjected to principal component analysis to assess chemical variability. The analysis identified three chemotypes in lemon peel oils, two in lemon leaf oils, four in lime peel oils, and four in lime leaf oils, based on key monoterpenes and oxygenated compounds. Keywords include Citrus, Rutaceae, lemon, lime, peel oil, leaf oil, GC, GC‑MS, 13C NMR, and principal component analysis.

Abstract

Peel and leaf oils of 43 taxa of lemons and limes were obtained from fruits and leaves collected from trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC-MS, and 13C NMR, and the results were submitted to principal component analysis to check for chemical variability. Three major chemotypes were distinguished for lemon peel oils: limonene; limonene/β-pinene/γ-terpinene; and limonene/linalyl acetate/linalool. Two chemotypes were identified for lemon leaf oils: limonene/β-pinene/geranial/neral and linalool/linalyl acetate/α-terpineol. In lime peel oils, four chemotypes were distinguished: limonene; limonene/γ-terpinene; limonene/β-pinene/γ-terpinene; and limonene/γ-terpinene/β-pinene/oxygenated products. Four others were identified for lime leaf oils: β-pinene/limonene; limonene/geranial/neral; limonene/linalool/citronellal; and limonene/sabinene/citronellal/linalool. These results were interpreted using principal component analysis. Keywords: Citrus; Rutaceae; lemon; lime; peel oil; leaf oil; GC; GC-MS; 13C NMR; principal component analysis