Mechanical and Permeability Properties of Edible Films and Coatings for Food and Pharmaceutical Applications

Use of natural polymers, such as proteins and polysaccharides, as coating or film materials for protection of food has grown extensively in recent years. These natural polymers can prevent deterioration of food by extending shelf life of the product and maintaining sensory quality and safety of various types of foods (Robertson 1993). Generally, film and coating systems are designed to take advantage of barrier properties of polymers and other molecules to guard against physical/mechanical impacts, chemical reactions and microbiological invasion. In addition, the use of natural polymers presents added advantages due to their edible nature, availability, low cost and biodegradability. The latter particularly is of paramount interest due to demand for reducing the amount of non-biodegradable synthetic packaging. Furthermore, these polymers can be easily modified in order to improve their physicochemical properties for filming and coating applications.