Pea starch may boost biodegradable packaging

The use of pea starch in the production of both edible and bio-packaging could allow food processors to further cut down on waste generated by their products, whilst also protecting against bacteria, according to new research.

In a study conducted by researchers at the University of Manitoba, Winnipeg, the starch, which was chosen due to its inherent gel strength, was tested as a key component in biodegradable packaging. According to the report, published in the Journal of Food Science, synthetic packaging materials are coming under criticism for creating environmental pollution, due to issues ensuring the products are recycled. By using biodegradable materials instead, manufacturers can further cut down on the amount of solid waste from food packaging heading to landfill sites, amidst regulatory pressure to ensure their operations are environmentally sustainable, the findings said. Report Author J Han and his colleagues tested packaging composed of 99 per cent pea starch and one per cent lysozyme under a number of production conditions to determine its suitability to store products. These conditions included using varying levels of moisture content between 30 per cent and 40 per cent, and different temperatures ranged between 70°C to 150°C during extrusion of the starch. The testing found that density in the extruded pea starch declined as temperatures were increased, while conversely lower moisture levels in the formula also resulted in declining product mass. The strength of the packaging was found to be related to higher density in the packaging, the researchers said. While increased temperatures were also found to reduce the effectiveness of lysozyme, the researchers added that the packaging still displayed sufficient antimicrobial activity to protect against the tested Brochotrix thermosphacta B2 microorganism. The report added that a combination of extruded pea starch containing lysozyme could potentially be used as a biodebradable material for packaging with antimicrobial activity. Despite these reported benefits, further testing on pea starch film to ascertain its moisture and gas barrier properties while using a plasticizer, was recommended by researchers before commercial manufacturing can begin. The research was conducted in conjunction with Canadian Grain Commission and supported by the Natural Sciences and Engineering Council of Canada. Source: the Journal of Food Science "Extrusion of Pea Starch Containing Lysozyme and Determination of Antimicrobial Activity" Published on-line ahead of print; doi:10.1111/j.1750-3841.2007.00513.x Authors: S. Nam, M.G. Scanlon, J.H. Han, M.S. Izydorczyk