Analysis of Kaffir Lime Oil Chemical Compounds by Gas Chromatography-Mass Spectrometry (GC-MS) and Z-Score Technique

Currently, the quality and grading of essential oil are done manually which is through sensory evaluation. It was performed based on the essential oil physical properties for example human experience and perception of the oil colour, odour, and long-lasting aroma. The sensory evaluation method is very subjective and may vary from one person to another such as a human sensory organ easily get fatigued to deal with repeatability experiment, the result obtained by trained grader usually is not consistent since it may vary to each other and the process itself is lengthy and high time-consuming. To face this problem, many researchers found that the chemical profile of the oil can be used to grad kaffir lime oil more accurately and save time. This study proposed analyses the chemical compound by gas chromatography-mass spectrometry (GC-MS) and Z-score technique from the 11 samples of kaffir lime oils with different brands in Malaysia. The chemical compounds in these samples were extracted by using GC-MS and being analyzed. The significant compound was identified by the Z-score technique. It was found that six chemical compounds such as Citronellal, Limonene, β-pinene, terpinene-4-ol, E-caryophyllene, and terpinolene were highlighted as significant for kaffir lime oil and can be used as a major compound in classifying the kaffir lime oil.