15 - Antimicrobial films and coatings for fresh fruit and Vegetables

Abstract

Edible films are generally defined as continuous matrices that can be prepared from edible materials, such as proteins, polysaccharides, and lipids. They can be used as film wraps or pouches for food or formed as film coatings on food or between food components. When consumed with the food, an edible film or coating becomes an ingredient of the food. Waxes such as carnauba wax have been used in fresh fruit and vegetable coatings to reduce moisture loss and add gloss since the 1930s in the United States. Edible films/coatings are also currently used in a variety of other applications, including collagen casings for sausages, chocolate coatings for dry nuts and fruits and shellac coatings for chocolates and other confectioneries. Interest in the application of edible coatings to fruits and vegetables has increased because they can be used to maintain fresh quality by controlling oxygen and carbon dioxide exchange between the product and the ambient atmosphere and by providing microbial stability for the product by incorporating antimicrobial agents. Both functional approaches reduce the vulnerability of the product to microbial decay. This chapter provides general information about edible films and coatings and their use with fruits and vegetables to reduce microbial growth. It reviews potential antimicrobial agents for antimicrobial films/coatings and summarizes methods for testing antimicrobial activity of films/coatings. It presents a summary of the results of scientific investigations of edible films and coatings that incorporate antimicrobials. The chapter focuses on edible coatings formed on fruits and vegetables. However, many of the investigations involve study of antimicrobials in edible films that have been formed independent of a fruit or vegetable surface.