ACS biocator. SCI. Eng.: sugar glass film can kill harmful bacteria in food

With the increase of antibiotic resistance, the problem of bacterial contamination of food is more and more serious Recently, scientists such as Carlos D M Filipe and m monsur Ali of McMaster University in Canada have developed an antibacterial "sugar glass" coating, in which a virus that destroys bacteria is embedded and can remain stable for three months This kind of coating can be used in food packaging and processing industry in the future, which will help to prevent foodborne diseases and deaths Phage is a virus that attacks bacteria and can infect and kill bacteria Unlike antibiotics, phages are specific to a single strain of bacteria, keeping the beneficial microorganisms safe For example, phages selectively purify cheese, a food that relies heavily on the presence of beneficial bacteria Because phages are naturally present in fruits and vegetables without affecting the smell, taste, safety or appearance of food, scientists are exploring whether these "bacterial eaters" can play a greater role in promoting food safety A typical phage structure (source: Wikipedia) however, embedding phages into food packaging is extremely challenging After drying, they can be added to various types of packaging films to kill the virus Other methods of stabilizing phage also have defects, which need special treatment or special equipment So Carlos D M Filipe, M monsur Ali and their colleagues tried to find a simpler way to stabilize and extend the shelf life of the virus embedded in the food coating The researchers embedded the phage into "sugar glass" film or pullulan polysaccharide film to extend the shelf life of fruits and eggs; trehalose and sucrose were used as freeze-drying stabilizers; or combined with two substances, they were dropped or coated on the packaging paper, and then dried overnight at room temperature for subsequent experiments The results showed that the phages embedded in the mixed film of pullulan polysaccharide and trehalose (source: ACS biomater SCI Eng.) lost their antibacterial effect in one or two weeks However, phages embedded in pullulan polysaccharide trehalose mixture can still infect bacteria after three months The relationship between antibacterial effect and time of different films (source: acsbiomater SCI Eng.) therefore, the scientists concluded that the combination of pullulan polysaccharide and trehalose has synergistic effect on the stability of phage, which is a very promising simple method to protect food from bacterial pollution Paper link: http://pubs.acs.org/doi/abs/10.1021/acsbiomaterials.7b00468