Chemists and food scientists at Rutgers, the State University of New Jersey, have developed natural approaches to the prevention of food contamination and spoilage.
Owing to a growing need and demand for greater food safety and natural or organic food products, the Rutgers researchers joined forces to build up natural ways in order to thwart food contamination and spoilage.
The researchers employed natural antimicrobial agents derived from sources such as cloves, oregano, thyme and paprika to create novel biodegradable polymers or plastics to potentially block the formation of bacterial biofilms on food surfaces and packaging.
Typically, a variety of bacteria will flock on a surface to form a bacterial community that exists as a slime-like matrix referred to as a biofilm. This kind of bacterial community is often described as being polymicrobial; it harbors multiple versions of infectious, disease-causing bacteria, such as Salmonella and E. coli.
"We mated natural substances with controlled-release, biodegradable polymers that could inhibit or prevent the formation of bacterial biofilms," explained Ashley Carbone, a graduate student at Rutgers who constructed the polymer compounds that were tested.
The research team said that this natural approach offers a number of advantages. The diversity of polymicrobial biofilms makes them difficult to defeat, with each type of microbe presenting a unique challenge to health and hygiene, explained Kathryn Uhrich, professor of chemistry and chemical biology and Carbone's adviser.
"The natural substances we chose have general antimicrobial activities against many different kinds of microorganisms," Uhrich said. "Therefore, the polymers into which we incorporated these natural substances have the potential to affect a much broader spectrum of microorganisms than organism-specific drugs," Uhrich said.
Another advantage comes out of the Rutgers researchers' decision to focus on the biofilms, rather than attempting to attack the individual bacteria. This avoids the potential of increasing the antimicrobial resistance of specific bacteria, an emerging problem in medical circles brought on by the overprescription of antibiotics.
An additional positive feature stems from the use of polymer "backbones" to which the natural agents were incorporated. These polymers are biodegradable due to their specific chemical composition and the nature of the bonds that hold them together, Uhrich explained.
"As they degrade in the presence of water and/or enzymes, they slowly release their active antimicrobials. A slow and controlled release of the food-based antimicrobial would offer great advantages in the food industry, providing protection over an extended time and extending the shelf-life of the food product," Carbone said.
Michael Chikindas, associate professor of food science at Rutgers and a co-investigator on the project, said that the retail marketing sector may benefit from the Rutgers innovation.
"If consumers buy products containing our natural bioactives, they will benefit from all the positive factors that come along with our new strategy for food safety. They will be eating foods that are safer for longer periods of time; they will not be expanding antibiotic resistance; and they will not be adding to their bodies' synthetic chemical load," Chikindas said.
The results of the study will be presented at the 234th national American Chemical Society meeting in Boston on Aug 22.