Transport phenomena in edible films

Abstract

Edible films and coatings help to control transfer of water vapor, oxygen, CO2, and active compounds between the food product and the environment providing additional protection during storage of fresh and processed food. Mass transfer phenomena are involved in these processes because edible films can act as functional interfaces between the food product and the environment. Edible films and coatings can also modify the heat transfer mechanism that takes place during food drying and frying, as well. In addition, they can function as controlled release packaging or active packaging-such packaging can be effectively impregnated with antimicrobial or antioxidant compounds, to deliver them over a stipulated period. Release and delivery of active compounds by these materials depend on the type of biopolymer that composes the film matrix and on the environmental conditions during storage. In a particular study, a turmeric dye extraction residue previously submitted to mechanical and chemical treatments was employed as coating in bananas. The treated turmeric residue coating effectively extended the coated banana shelf life by 4 days as compared to uncoated bananas.