Copper nanoparticles

Copper nanoparticles show promise for active packaging

Active packaging continues to move ahead, such as the emerging incorporation of non-contact antimicrobials in the package structures to suppress pathogens and prolong shelf life. News from Michigan Technological University is an innovation that has the potential to kill 100 percent of harmful microbes before they even touch produce. The secret is copper – an element long valued for its antibiotic properties.

Jaroslaw Drelich, a professor of materials science and engineering, is behind a new food protection method that relies on copper nanoparticles embedded in vermiculite – an inert compound found in mixtures such as potting soil. Preliminary testing yielded positive results: 100 percent of E. coli bacteria were eliminated from a sample of local lake water. The copper also proved effective in killing Staphylococcus aureus, the bacteria responsible for staph infections.

But the metal is also lethal to a number of other pathogens, including antibiotic-resistant bacteria, viruses and fungi – Listeria, Salmonella and MRSA, to name a few. For this reason, the copper-vermiculite nanoparticles could prove effective along the entire spectrum of food-borne disease.

The material could be incorporated into food packaging materials like cardboard, plastic, and even cellulose-based egg cartons. At about $0,25 per 500g, Drelich’s innovation could prove a cost-efficient way to dramatically improve the safety of fresh produce as well as other foods.

However, its potential does not stop there.

“When you make a discovery like this, it’s hard to envision all the potential applications,” said Drelich. “It could even be mixed into that wad of dollar bills in your wallet. Money is the most contaminated product on the market.”

Additional areas of application include drinking water, sewage and industrial effluent. “I’ve had inquiries from companies interested in purifying water,” he added.

Drelich is now working with Michigan Tech SmartZone to commercialise the nanoparticle material. He hopes to license it to food packing companies.

According to the Center for Disease Control and Prevention (CDC), one in six Americans get sick with food borne illness each year – 48 million people, of whom 128,000 are hospitalized and 3,000 die. The most common pathogens are norovirus, Salmonella, Clostridium perfringens and Campylobacter.

Journal Reference:
Drelich’s initial research on the copper-vermiculite materials is described in the article “Vermiculite Decorated with Copper Nanoparticles: Novel Antibacterial Hybrid Material,” published in 2011 in Applied Surface Science.

Source: Michigan Technological University