Covalent linkage of bioactive volatiles to a polysaccharide support as a potential approach for preparing active edible coatings and delivery systems for food products

Abstract

In this study, a potential of covalent linkage approach for developing active edible coatings was examined. Vanillin and trans-cinnamaldehyde were bound to chitosan by Schiff base reaction and reductive amination. The modified polysaccharides were comprehensively characterized and applied as active coatings on fresh-cut melon. The covalent linkage allowed overcoming solubility problems with the lipophilic vanillin and cinnamaldehyde and neutralizing their volatility, producing well-adhered coatings that enhanced fruit quality and storability without sensorial impairment. The attached hydrophobic moieties also provided new polysaccharides with self-assembling ability. Their aggregates were loaded with antimicrobial citral and added to mandarin juice, resulting in up to 6 log CFU/mL microbial count reduction. Thus, the covalent linkage concept offers several advantages, especially when hydrophobic or volatile active agents are used. Further developed, it may become a safe and effective tool for the formation of advanced active edible coatings and delivery vehicles for direct applications on food products.