Distribution of Volatile Compounds in Kaffir Lime (Citrus hystrix) Leaves Grown in Soilless Substrate Analyzed Using Electronic Nose

Abstract

Objective: The key objective of this research is to investigate the aroma profle of Kaffir lime (Citrus hystrix) leaves grown under greenhouse and peatlite soilless substrate conditions using the electronic nose system. Methodology: Fresh Citrus hystrix samples of recently matured (RML) and old (OL) leaves were analyzed using electronic nose. A total of 79 volatiles were identified and those equivalent to 90% were reported. Results: The RML and OL leaves had similar volatiles such as Citronellal, N-Nonanal, Myrcene, Pentyl Octanoate and γ-Terpinene with no significant difference in the concentration. Citronellal was the major volatile found more than 20% in both recently matured and old leaves. Recently matured and old leaves also had dissimilar volatiles such as 5-Propyldihydro-2(3H)-Furanone(32.9%), β-Pinene (7.6%), Terpinen-4-ol (2.4%), 1-Hexanol (1.3%) and (Z)-3-Hexen-1-ol-Acetate (1.0%) were only found in the recently matured leaves, whereas 1-Nonanol (30.8%), 3-Methyl Butanoic Acid(4.6%), p-Methyl Acetophenone (1.5%), Trans-Hex-2-Enyl Acetate (1.4%) and Methyl Eugenol (1.1%) were detected only in OL. Conclusion: The results are very useful in food and cosmetics industries to develop innovative products based on kaffirlime leaves/oil.