Protein sources such as albumin and whey can be used to make bioplastics with significant antibacterial properties, according to a recent study. The new materials could be used for food packaging, as well as medical applications such as wound-healing dressings, sutures, catheter tubes and drug delivery.
Researchers at the University of Georgia tested three possible sources of raw material for bioplastic production: albumin, whey and soy proteins. They examined the thermal, viscoelastic and antibacterial properties of the three proteins when blended with a traditional plasticizer such as glycerol.
Results showed that albumin-glycerol and whey-glycerol bioplastics had the best antibacterial properties.
"It was found that it had complete inhibition, as in no bacteria would grow on the plastic once applied," said Alex Jones, a doctoral student in the department of textiles, merchandising and interiors. "The bacteria wouldn't be able to live on it."
As well as offering an alternative to conventional petroleum-based plastics that pose risks of contamination, the product is fully biodegradable.
"If you put it in a landfill, this being pure protein, it will break down," Jones explained. "If you put it in soil for a month — at most two months — these plastics will disappear."
Next, the researchers hope to scale up production of the bioplastics for use in food packaging and biomedical applications.
Their findings have been published in the Journal of Applied Polymer Science.