Enhancing the functionality of edible coatings by enrichment with phenolics for the preservation of foods

The use of edible biopolymeric materials (zein, whey proteins, soy proteins, chitosan, alginate, carrageenan, pullulan, cellulose) enriched with natural antimicrobial compounds provides a promising alternative method to inhibit the growth of pathogenic and spoilage microorganisms in food and to increase safety and quality of food products. The use of natural phenolic agents in edible films has become increasingly popular since these compounds have not only antimicrobial properties, but they also exert different bioactive effects on human, including antioxidant activity. Phenolics interact with the polymeric matrix through hydrogen bonds, that generates a slow-release mechanism in the surrounding environment. Competency of phenolics, in extending the shelf-life still require further attention, particularly in terms of the spectrum of antimicrobial action, and stability of developed active coatings.

The antimicrobial activity of several phenolic compounds will be evaluated both in purity and in mixtures in order to highlight possible synergies. The spectrum of antimicrobial action will be evaluated against spoilage or pathogenic microorganisms potentially occurring on fresh foods (e.g., fruits, vegetables, meat) and processed foods (e.g., bread, cheeses). Next, the interaction between the phenolic compound and the polymer matrix will be evaluated. Finally, protocols for assembling the active edible coating will be optimized. The effect of the active coating will also be tested under conventional processing and storage conditions specific to each selected model food. The latter activity will allow the introduction of corrective elements in the assembly and application of the active coating.

The main expected results are linked to the evaluation of the efficacy of the active edible coatings, and to the definition of protocols that are readily transferable to companies in the agribusiness sector.