Enhancement of agricultural produce quality and storability using citral-based edible coatings; the valuable effect of nano-emulsification in a solid-state delivery on fresh-cut melons model

Emulsification approach is widely employed to deliver beneficial agents to liquid food products, whereas utilizing emulsions with solid food is scarce. In this research, coarse and nano emulsions of citral were prepared and embedded in chitosan or carboxymethyl cellulose (CMC) polysaccharides to form active edible coatings for solid-state delivery. Polysaccharides stabilized the emulsions by electrostatic interactions, while chitosan also prevented coalescence. The nano emulsion based films showed a more organized and dense morphology (E-SEM), higher water vapor barrier, better mechanical features (strength, elasticity and Young modulus) than the coarse ones. When applied on a solid food model, fresh-cut melons, the nanoemulsified edible coatings demonstrated a superior antimicrobial protection (up to a 5-log reduction) and significantly extended product's storability (up to 13 days). The presented approach could be further employed for the delivery of other beneficial agents (nutrients, aroma, antimicrobial, antioxidants) to solid food products, contributing a general progress in this field.