Up until recently, the $100 million-plus edible film and coating industry has mainly focused on antimicrobial coatings that can keep fruits and vegetables fresh longer—but researchers are starting to branch out into other food products, and testing different vehicles than the traditional proteins, polysaccharides, fats, and waxes.
The latest? Essential oils to maintain the freshness of bread and meat.
In one study, published in the Journal of Agricultural and Food Chemistry in early May, researchers at the Federal University of Viçosa in Brazil created an edible film by incorporating oils found in cloves and oregano into water-soluble polymers, and used it to treat preservative-free bread. They found that both essential oils slowed the growth of mold on the bread for 15 days—longer than a commercial preservative, which lost its effectiveness after 10 days.
Meanwhile, investigators at the College of Agricultural Sciences at Penn State University have been hot on a related trail. They treated fresh and ready-to-eat meat and poultry products with bacterial pathogens then coated them with an edible polymer film containing 2 percent oregano essential oil, 2 percent rosemary essential oil, zinc oxide nanoparticles, or silver nanoparticles.
“The results from this study demonstrated that edible films made from pullulan and incorporated with essential oils or nanoparticles have the potential to improve the safety of refrigerated, fresh, or further-processed meat and poultry products,” says Cutter, PhD, professor of food science. “The research shows that we can apply these food-grade films and have them do double duty—releasing antimicrobials and imparting characteristics to protect and improve food we eat.”
Dr. Cutter’s research was published online in the April issue of the Journal of Food Science.