As if it's not enough that fresh produce may sometimes be tainted with harmful bacteria, those microbes can get transferred onto other fruits and veggies, contaminating them too. A new coating, however, has been designed to keep the latter from happening.
Led by Assoc. Prof. Mustafa Akbulut, a team at Texas A&M University created the coating by first using high heat to attach a layer of silica to the surface of an aluminum sheet – aluminum was chosen because it's frequently used in the food-handling industry for items such as tables, buckets and roller-type conveyors.
Onto that substrate, the scientists then added a mixture of more silica and a naturally occurring antimicrobial protein known as lysozyme. The resulting two-layer coating not only kills bacteria on contact, but when viewed with a microscope, it also has a rough texture that causes water to bead up and roll off. Because bacteria typically require water in order to stick to surfaces and multiply, this hydrophobic (water-repelling) texture helps boost the antibacterial effect.
When the coating was tested alongside untreated aluminum in identical conditions, it was found to host 99.99-percent fewer Salmonella typhimurium and Listeria innocua bacteria.
It should also last longer than existing antimicrobial coatings, although it will still need to be periodically reapplied. With that limitation in mind, Akbulut and colleagues are now working on developing a semi-permanent version of the technology.
Their findings are outlined in a paper that was recently published in the journal ACS Applied Materials & Interfaces.
Source: Texas A&M University
