Antifungal and anti-termite activities of emulsified and encapsulated Liquidambar excelsa balsam essential oil for wood protection application

The high demand for wood in Indonesia is obstructed by the low natural durability of fast-growing wood against biodeterioration agents, which has previously been addressed with synthetic preservatives. The environmental impact of synthetic preservatives was reduced by developing the essential oil from Liquidambar excelsa balsam exudate as an alternative natural preservative derived from non-timber forest products. Therefore, this study aimed to evaluate the effectiveness of emulsion and encapsulation formulations of L. excelsa essential oil in increasing wood resistance against Schizophyllum commune and Coptotermes curvignathus . Exudate induction was carried out using 10% (v/v) methyl jasmonate, followed by distillation of the essential oil, which was formulated in both emulsion (Tween 80 and ethanol) and encapsulation (poly-ε-caprolactone polymer and Tween 60) systems. The result of the characterization showed that the particle diameter was in the sub-micron phase. In vitro tests showed that the 5% (v/v) emulsion had the best antifungal inhibitory power of 58.74%, which was increased compared to pure essential oil (16.13%). The application of 5% (v/v) encapsulation to Paraserianthes falcataria and Anthocephalus cadamba wood during testing provided the highest protection, with weight losses of 7.05% and 2.46%, respectively. Meanwhile, toxicity tests against termites showed increasing mortality with rising concentration. The 5% (v/v) encapsulation led to achievement of 84.89% mortality, which was higher than the use of pure essential oil (80.89%). The emulsion and encapsulation formulation effectively increased the bioactivity of L. excelsa essential oil, making it a promising technology for increasing the lifespan of fast-growing wood.