Sustainable design and characterization of Aegle marmelos fruit nanomucilage-flaxseed oil nanoemulsion: Shelf-life of coated fresh-cut papaya

Nanoemulsions made from polysaccharides sourced from unconventional materials have gained attention as efficient delivery systems for bioactive compounds, aiding in their enhanced absorption. Therefore, this research was primarily focused on developing an economical and environmentally sustainable method for the preparation of nanoemulsion and the evaluation of its characteristics. Moreover, the synthesized nanoemulsion was assessed for its synergistic antibiofilm effects and its application as a coating material on fresh-cut papaya fruits. Aegle marmelos mucilage, flaxseed oil, and Tween 80 were utilized for the formulation of nanoemulsion by the low-energy method. Flaxseed oil analysis confirmed the existence of key fatty acids, including stearic acid, oleic acid, alpha-linolenic acid, linoleic acid, and palmitic acid. The optimized nanoemulsion (NM3) exhibited an average droplet size of 119.16 +/- 5.38 nm with -25.20 +/- 0.99 mV of surface charge. In addition, NM3 stability was investigated by subjecting it to different storage temperatures, pH levels, and NaCl concentrations by measuring the changes in zeta potential and droplet size. The NM3 nanoemulsion demonstrated significantly higher changes in stability (p < 0.05) at different pH levels and ionic strengths (p < 0.05). The FTIR results inferred the majorly existing functional groups at 3339.05 cm(-1), 2127.88 cm(-1), 1636.64 cm(-1), and 589.27 cm(-1). Furthermore, the SEM images also revealed a uniform distribution of droplets throughout the nanoemulsion. When the nanoemulsion was applied to fresh-cut papaya fruits, it effectively delayed weight loss and also affected the titratable acidity content and total soluble solids (TSS), thereby reducing spoilage. In conclusion, this study demonstrated that the nanoemulsion exhibited superior antimicrobial effects and great potential for the shelf-life improvement of fresh-cut papaya fruits. Thus, combining oils with mucilage represents a promising approach to enhancing the effectiveness of antimicrobial activity and controlling foodborne pathogens.