ABSTRACT

Packages have become an essential element in current developed societies. In particular, food packaging has experienced an extraordinary expansion, because most commercialized foodstuffs, including fresh fruits and vegetables, are being sold in packages. Over the last few decades, the use of polymers, as food packaging materials, has increased enormously due to their advantages over other traditional materials such as glass or tin plate. A great advantage of plastics is the large variety of materials and compositions available, which makes it possible to adopt the most convenient packaging design to the very speci c needs of each product. Relevant characteristics of plastics are, for example, low cost, low weight, good thermosealability, ease of printing, and the fact that they are microwaveable. They can also be conformed into an unlimited variety of sizes and shapes, and converters can easily modify them. The optical properties (brightness and transparency) can also be

adapted to the speci c requirements of the product and allows the consumer to see the packaged product, providing it with a nice appeal (López-Rubio et al. 2004).