Applications of Starch-Based Films in Food Packaging

Abstract

This article provides an overview of production methods of starch-based films, proposed polymer morphology of films, and factors controlling mechanical, barrier, and thermal properties of starch-based films. Applications of starch-based films in food packaging are discussed. Starch-based films can be produced using either a solvent casting process or extrusion. The production methods, types and content of starch and plasticizer, and amylose content govern polymer morphology of starch films resulting in films exhibiting different thermal, mechanical, and barrier properties. The economical starch-based films generally exhibit high oxygen barrier properties but poor moisture barrier properties. The films are also tasteless, colorless, and odorless. The most common use of starch-based films for food packaging is food coating. Fruits and vegetables are favorably coated by starch film due to their barrier properties. Edible starch coatings are also applied for other types of foods for shelf life extension and quality maintenance. Also, numerous ingredients have been added into starch-based films in order to contribute additional functions to the films. The three major purposes of the auxiliary ingredients are antimicrobial, antioxidant, and a carrier of flavors/active ingredients. The ingredients can be added directly to the starch-based films by direct blending and/or surface coating. In addition, the ingredient encapsulation and ingredient incorporation into the other polymer matrix prior to blending with starch are other options. Starch-based films are the most frequently used for fruits, meat, and dairy products as food packaging.