Stability and Shelf-Life Modeling of Lemongrass Essential Oil-in-Water Nanoemulsions

Abstract

This study investigates the stability and shelf life of lemongrass essential oil-in-water (LGEO/W) nanoemulsions, a rich source of bioactive compounds (e.g., citral and citronellal) and a promising natural preservative. Initially, LGEO/W emulsions were produced through premix membrane emulsification (PME) and traditional methods such as high-pressure homogenization (HPH) and ultrasonication (US) to generate micron- and nano-sized emulsions. Subsequent investigations focused on assessing the stability of nanoemulsions under various storage temperatures, employing a range of physicochemical and antimicrobial tests. Results revealed that neither the emulsification technique nor emulsion droplet size (in the range of 0.1 to 10 µm) affected the antioxidative or antimicrobial properties of LGEO/W emulsions. Additionally, a combined approach of principal component analysis and traditional reaction kinetics was employed to examine the decline in antioxidative activity of PME-generated nanoemulsions, to model the quality degradation kinetics over time under various storage temperatures. These findings offer valuable insights into the production, stability, and application of LGEO/W nanoemulsions, highlighting their potential as effective natural preservatives.