The Comparison Between Different Extraction Methods for Essential Oil of Lemongrass, Cymbopogon Citratus and Its Effectiveness Against Ganoderma Boninense

Lee, Syuan Khai (2024) The Comparison Between Different Extraction Methods for Essential Oil of Lemongrass, Cymbopogon Citratus and Its Effectiveness Against Ganoderma Boninense. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

Text Lee Syuan Khai_Full Text.pdf Restricted to Registered users only Download (6MB)

Abstract

Essential oils are natural volatile liquid products derived from aromatic plants that consist of a complex chemical composition, mainly lipophilic terpene based compounds. Essential oils have medicinal applications such as antioxidant, antimicrobial and antifungal properties, making them an attractive area of research for the biological control of diseases. Ganoderma boninense is a white rot basidiomycete fungus that is the primary causative agent of Basal Stem Rot in oil palm. Difficult detection and control of the disease has proven detrimental to the oil palm industry. Hence, this project aims to compare the extraction methods of lemongrass (C. citratus) essential oil and investigate its effectiveness towards inhibiting G. boninense in vitro. Hydrodistillation and Soxhlet extraction methods were carried out on 50 g of lemongrass samples and the percentage yield of oil was compared and stored at 4℃. Antifungal assay against G. boninense was carried out by the poisoned-food technique using essential oil concentrations of 0.2, 0.4, 0.6, 0.8 and 1.0 μL/mL incorporated into agar. Colony diameter was measured across 7 days and percentage inhibition of mycelial growth was calculated. Results showed that Soxhlet extraction yielded higher quantity of oil (15.62%) but hydrodistillation yielded higher quality in terms of bioactive compounds such as citral, geraniol. Antifungal assay results showed inconsistent trends in percentage inhibition with the highest percentage of 13.49% ± 19.18 for 0.6 μL/mL at day 7. Furthermore, fungal contamination beginning on day 4 significantly affected the average colony diameters of treatments 0.2, 0.4, 0.6 and 0.8 μL/mL in the later days. In conclusion, lemongrass essential oil extracted from Soxhlet extraction was higher than hydrodistillation and was overall not effective in inhibiting the growth of G. boninense.