Among the enemies that endanger consumer foods, Listeria monocytogenes stands out as one of the most dangerous pathogens, causing dozens of deaths each year. It can contaminate everything from processed meats to unpasteurised dairy products and ready-to-eat foods; it has the ability to survive in extreme conditions, with low temperatures and high levels of salinity, and is responsible for serious illnesses, especially in immunocompromised people, pregnant women, the elderly and children. In addition to generating waste, traditional methods of control can be harmful to health, and its control is a challenge for the food industry.
Now, a research team from the Institute of Agrochemistry and Food Technology (IATA-CSIC) at the University of Valencia Science Park, in collaboration with the Institute of Molecular and Cellular Biology of Plants (IBMCP, CSIC-UPV), has found a formula to fight this bacterium by combining two enzymes. "It is a harmless system free of harmful residues, which effectively eliminates up to 99.99% of listeria cells in tests and has great potential for direct application in food," says Julia Marín, biochemist, researcher at the University of Valencia at the IATA and leader of the study published in the journal Biomolecules. ‘Separately, these enzymes have limited efficacy, but together they achieve an excellent synergistic effect against Listeria monocytogenes, because they have different modes of action,’ she adds.
"The strategy used is very effective for cleaning surfaces in food environments, and has great potential for direct application to food in the future", Julio Polaina, member of the IATA-CSIC research team
This combination has also made it possible to reduce the concentrations of glucose oxidase and endolysin to achieve an antimicrobial effect, minimising possible adverse effects on the characteristics and organoleptic properties of the food. "The strategy used is very effective for cleaning surfaces in food environments, and has great potential for direct application to food in the future," adds Julio Polaina, a member of the IATA-CSIC research team.
Moreover, "the likelihood of bacteria developing resistance to both enzymes simultaneously is low, given the combined and specific nature of the treatment," concludes Polaina. "This approach is not only effective, but also environmentally friendly. Unlike traditional chemical disinfectants, these enzymes are not toxic, nor do they generate hazardous waste," adds José Antonio Darós, a CSIC researcher at the IBMCP who is participating in the research.
"The ‘enzyme cocktail’ used in this research represents a novel method with great potential as a disinfectant agent and as a food preservative for companies in the food sector", David Talens, IATA-CSIC researcher participating in the study
"The ‘enzyme cocktail’ used in this research represents a novel method with great potential as a disinfectant agent and as a food preservative for companies in the sector," summarises David Talens, IATA-CSIC researcher participating in the study.
The results obtained have given rise to a patent owned by the Consejo Superior de Investigaciones Científicas (62.5%), the Universitat de València (25%) and the Universitat Politècnica de València (12%). "The treatment developed represents a potential revolution in the fight against food pathogens. Although further research is needed to scale up these results to the industrial level, the prospects are encouraging", agree the members of the scientific team.