Application of Lemongrass Essential Oil as a Natural Preservative Agent for Pineapple Juice

Pineapple juice is frequently consumed for its extensive health benefits, but is prone to microbiological degradation. Pasteurization – as a current preservation technique – have been degrading the nutritional qualities of fruit juices, and the use of synthetic preservatives have been perceived negatively by consumers. In this study, lemongrass essential oil was applied for the preservation of pineapple juice. Agar Well Diffusion Method was used for antimicrobial activity screening of lemongrass essential oil against E. coli, S. cerevisiae, and A. niger, while Broth Macrodilution Method was used in determining Minimum Inhibitory Concentration (MIC) of lemongrass essential oil, which was evaluated to be 0.1%. Furthermore, the addition of 0.1% lemongrass essential oil into pineapple juice had a negative impact regarding the sensorial acceptability, but was able to significantly suppress the microbial count for bacteria, yeast, and mould during 5 days of storage time in chilling temperature (4oC). Vitamin C content degradation and pH changes during storage were not significantly affected by the addition oflemongrass essential oil. Furthermore, the addition of 0.1% lemongrass essential oil was observed to be not synergistic with the enzyme activity of pineapple juice, and has negatively impacted the enzyme stability of the pineapple juice.