Researchers have developed a reliable method for detecting silver nanoparticles in fresh produce and other food products.
Is there a need for that? Perhaps. Over the last few years, the use of nanomaterials for water treatment, food packaging, pesticides, cosmetics and other industries has increased. Farmers have used silver nanoparticles as a pesticide because of their capability to suppress the growth of harmful organisms - but it is unknown if these particles pose a potential health risk to humans and the environment.
The researchers studied the residue and penetration of silver nanoparticles on pear skin. First, the scientists immersed the pears in a silver nanoparticle solution similar to pesticide application. The pears were then washed and rinsed repeatedly.
Results showed that four days after the treatment and rinsing, silver nanoparticles were still attached to the skin, and the smaller particles were able to penetrate the skin and reach the pear pulp.
Graduate student Zhong Zhang applies silver nanoparticles to a piece of fruit. In a recent study, University of Missouri researchers found that these particles could pose a potential health risk to humans and the environment. Credit: University of Missouri
"More than 1,000 products on the market are nanotechnology-based products," said Mengshi Lin, associate professor of food science in the MU College of Agriculture, Food and Natural Resources. "This is a concern because we do not know the toxicity of the nanoparticles. Our goal is to detect, identify and quantify these nanoparticles in food and food products and study their toxicity as soon as possible.
"The penetration of silver nanoparticles is dangerous to consumers because they have the ability to relocate in the human body after digestion. Therefore, smaller nanoparticles may be more harmful to consumers than larger counterparts."
When ingested, nanoparticles pass into the blood and lymph system, circulate through the body and reach potentially sensitive sites such as the spleen, brain, liver and heart.
The growing trend to use other types of nanoparticles has revolutionized the food industry by enhancing flavors, improving supplement delivery, keeping food fresh longer and brightening the colors of food. However, researchers worry that the use of silver nanoparticles could harm the human body.
"This study provides a promising approach for detecting the contamination of silver nanoparticles in food crops or other agricultural products," Lin said.
Upcoming in Journal of Agricultural Food Chemistry, no DOI yet
