Development of eugenol nanoemulsion loaded shellac-based formulations for extending postharvest shelf-life of Kaji lemon (Citrus jambhiri)

Abstract

Kaji lemon (Citrus jambhiri) is a variety of lemon known for its high concentration of ascorbic acid, natural compounds, and cholesterol-lowering effects. However, a lack of appropriate postharvest storage can negatively affect lemon fruits’ shelf life and marketability, causing significant quality loss. Shellac wax is well-known for its film-forming, water-resistant, and gas- and moisture-barrier properties, which can be used as a coating material. In this research, shellac wax-based coating formulations were prepared by incorporating Aloe vera (AV) gel and eugenol as antioxidant and antibacterial agents to preserve the postharvest qualities of Kaji lemons during postharvest storage. The effectiveness of the coated fruits was determined by assessing various physicochemical quality parameters, including weight loss, total soluble solids, firmness, pH, acidity, and decay index, periodically at 5-day intervals during ambient storage. The obtained results revealed that the fruits treated with shellac wax containing eugenol nanoemulsion (ENE) and AV exhibited promising outcomes and prolonged shelf life of the fruits for 21 days with minimal weight loss, maintained firmness, and exhibited the least decay during ambient storage conditions. Moreover, the incorporation of eugenol oil nanoemulsion and AV gel into the coatings improved their physicochemical and functional characteristics, including enhanced antimicrobial activities against foodborne bacterial pathogens (Escherichia coli and Bacillus subtilis).