Scientists are investigating whether these “bacteria-eaters” could have an expanded role in promoting food safety.
A team of researchers in Canada have developed an antibacterial “sugar-glass” coating in which viruses that destroy bacteria are embedded and are kept stable for up to three months. The coating could someday be used in the food packaging and processing industries to help prevent food-borne illnesses and deaths.
Bacteriophages are viruses that infect and kill bacteria. Unlike antibiotics, phages specifically target single strains of the bacterial germs, leaving beneficial microbes unharmed.
Phages are useful for selectively decontaminating cheese — a food that relies heavily on the presence of beneficial bacteria for its flavor. Because phages are naturally found on fruits and vegetables and do not affect the odor, taste, safety or appearance of foods, scientists are investigating whether these “bacteria-eaters” could have an expanded role in promoting food safety.
The researchers embedded phages into soluble “sugar glasses” or films made with pullulan, a polysaccharide used to prolong the shelf life of fruits and eggs; trehalose, a sugar used as stabilizing agent in freeze drying; or a combination of two substances.
Then, they drop-cast or coated the mixtures onto butcher paper and allowed them to air dry overnight at room temperature. Phages embedded in pullulan or trehalose alone lost their antibacterial effects within one or two weeks. But those embedded within the combined pullulan-trehalose mixture could still infect bacteria up to three months later.
The researchers concluded that the pullulan-trehalose combination had a synergistic effect on bacteriophage stability and is a promising, simple method for protecting food from bacterial contamination.
