The primary role of packaging is to maintain the quality and safety of food under certain conditions for a specific period of time, as well as to provide identification and information. Deterioration in food is caused by physicochemical and microbiological changes since fresh foods after harvest or slaughter are still active biological systems. This results in color, texture and flavor changes, and in some cases possible toxicity of the food product.

Plastics are becoming the most important packaging material for food products because of their unique characteristics: mechanical strength, light weight, relatively low cost, and ease of processing and manufacturing. Consequently, the impact of plastics on the environment has gained significant attention within the food industry, governments and consumers.

Containers made from bioplastics have the potential to reduce environmental problems related to the use of packaging made from petroleum-based plastics, e.g. by reducing the amount of waste in landfills. In addition, bioplastics are made from renewable resources, reducing dependence on declining petroleum-based ones. Furthermore, consumers are more inclined toward purchasing food in bio-based packaging materials.

The need for this type of packaging has created an explosive growth of research in bioplastics over the past decade in the U.S. and the rest of the world. Some of these bioplastics are already available in the marketplace while others are currently under development. 

Although bioplastics are receiving more attention as materials for food packaging applications, the use of this new generation of plastics requires an understanding of the complex interactions between product and packaging material resulting from permeation, sorption (scalping) and desorption (migration), as well as the effect of the surrounding environment (temperature and relative humidity). These interactions result in changes in the packaging material (e.g. color, permeability, thermal transitions, mechanical properties) and/or the quality and safety of the food product (e.g. flavor, texture, weight loss, microbial growth). 

Recognizing the lack of knowledge in this area, a research team led by Dr. Eva Almenar at the School of Packaging, Michigan State University, has been studying the interaction between food and bioplastics.

Almenar will lead a presentation on this topic during Process Expo at Chicago’s McCormick Place, Nov. 3-6, 2013. The course will address the current possibilities and limitations of bioplastics as food packaging materials, and will feature polylactic acid (PLA) as an example of a commercially available material, and proteins as an example of a material currently under development. The mechanical, physical and barrier properties of these new materials will be compared to those of conventional polymers used in food packaging. 

Other topics for discussion include:

• Retail shelf life (physicochemical, microbiological and sensorial changes) of food products packaged in containers made from bioplastics,

• Diffusion of bioplastic components (e.g. proteins, plasticizers) into different food matrices,

• The effect of the food matrix on the bioplastic structure,

• The use of nanotechnology (e.g. nanoclays) and coating technology to improve some bioplastics for suitability as food packaging, and

• Studies on consumer appeal of food products packaged in bioplastic containers.

All in all, this talk offers an excellent opportunity for all stakeholders in the food packaging supply chain to gain insights into the status of one bioplastic currently available as food packaging, as well as others now under development.