Characterization and stability study of lemongrass oil blend microemulsion as natural preservative

Abstract

Food preservative plays an important role in maintaining food quality and extending shelf life. Essential oils as natural preservatives are preferred due to its pose as less harmful to human as compared to chemical preservatives. The objective of this study is to evaluate the effectiveness of lemongrass oil blend microemulsion by studying its physical properties, stability and antibacterial efficacy in curry paste. Ternary phase diagram is constructed via phase titration method for the microemulsion formulation. Microemulsion technology improves the effectiveness of lemongrass essential oil by stabilizing and preserving its own natural benefits. The antibacterial compounds identification was elucidated by GC-MS. The overall results concluded that lemongrass oil blend microemulsion shows transparent appearance, low acidity (pH 4.1 - 5.1), moderate conductivity (18 - 58 μS/cm), low viscosity (<4 mPa second) and high stability. It can be an alternative for natural preservative with all the traits obtained in this study with an additional antibacterial effect by d-limonene, citronellal, citronellol and citral.