A Purdue University research team developed a nanoparticle that can hold and release an antimicrobial agent as needed for extending the shelf life of foods susceptible to Listeria monocytogenes.
Yuan Yao, an assistant professor of food science, altered the surface of a carbohydrate found in sweet corn called phytoglycogen, which led to the creation of several forms of a nanoparticle that could attract and stabilize nisin, a food-based antimicrobial peptide. The nanoparticle can then preserve nisin for up to three weeks, combating Listeria, a potentially lethal foodborne pathogen found in meats, dairy and vegetables that is especially troublesome for pregnant women, infants, older people and others with weakened immune systems.
Controlling Listeria at deli counters, for example, is especially problematic because meat is continually being opened, cut and stored, giving Listeria many chances to contaminate the food. Nisin alone is only effective at inhibiting Listeria for a short period – possibly only a few days – in many foods.
Yao and his colleagues are working on using other food-based antimicrobial peptides and nano-constructs to combat Listeria other foodborne pathogens such as E. coli O157:H7 and salmonella. The U.S. Department of Agriculture and the National Science Foundation funded their research.