US researchers develop steel pack coating to fight food contamination

14 Feb 2024 --- Researchers at Texas A&M University College of Engineering, US, have developed a metal coating solution for food-grade packaging. To improve product safety in the food industry, the scientists developed a two-step coating solution for galvanized steel that is more hygienic than stainless steel-based packaging and reduces the risk of corrosion.

Galvanized steel containers and surfaces are used for harvested produce due to durability, strength and lower cost compared to stainless steel, but bacteria residing in storage containers can cause corrosion, explain Dr. Mustafa Akbulut, professor of Chemical Engineering, and Dr. Luis Cisneros-Zevallos, professor of Horticultural Science, who conducted the study. 

The new coating will reduce corrosion by a minimum of 70%, asserts Akbulut. “This material is more durable and doesn’t experience corrosion. The surface itself can repel the bacteria so it doesn’t get germs stuck on it. Normal steel tends to collect pathogens and microorganisms, but the coated steel is overcoming that issue. These are the main benefits of this technology.” 

The coating method for galvanized steel exhibits superhydrophobicity and antifouling capabilities, effectively inhibiting the attachment of fungi, bacteria and mud. The research was published in the Journal of Food Engineering.

Consumers trust that they are buying safe products that will not negatively affect their health.Applicable to food-storage units
Cisneros-Zevallos says the findings will have a positive impact because the people who consume fruits and vegetables trust that they are buying safe products that will not negatively affect their health.

“Right now, the industry does their best to reduce those risks, but you will hear about outbreaks of these contaminations and people getting sick. There are sometimes reported deaths because of these events,” he says.

During the coating process, the material properties, structural properties and mechanical strength of steel do not change. “Only the very top layer of the steel is coated, since that is where food comes in contact with the surface,” adds Akbulut.

Research shows that this coating decreases bacterial strains over seven days and reduces the adherence to Aspergillus, a food-borne fungi.

The coating technology can potentially be used on grain storage silos, along with other food-related storage units and containers, according to the researchers. “This is a significant boon to the multidisciplinary fields of food engineering, safety and processing,” they say.

Agricultural benefits 
Akbuluth says the galvanized steel coating will also benefit agricultural farmland.

“Many of the food-produced commodities come to the industrial setting in some sort of soil, debris or mud. Even if the produce is washed, these commodities can cause contamination. With this technology, we are reducing mud-related contamination,” he explains.

With the information gathered from the research, Cisneros-Zevallos says they could eventually adapt and utilize these technologies to revolutionize fewer outbreaks and positively impact the food industry.

“Our goal is to make the industry adopt this. Processors will benefit in the sense that they will be handling something that they can deliver in a trustful way to consumers, and consumers will benefit because they will have something that will be safe for them.” 

From the field to the consumer, contamination can be minimized by using these kinds of surfaces and avoiding cross-contamination.

“With this research, we are ensuring that technological developments from other fields are being pursued and implemented in agriculture. The agricultural field is catching up with other technologies. This coating directly impacts our daily life and the food we're trying to make safer,” concludes Cisneros-Zevallos.

Edited by Natalie Schwertheim