Phages as biocontrol agents in dairy products

Phages are ubiquitous in the environment and have been used successfully as biological control agents against pathogenic microorganisms in some food systems. However, the use of phages for biocontrol strategies at a commercial scale in the food industry as a whole still faces some challenges. Better strategies to address interference by food matrices and environmental conditions still need to be found. The basic mechanisms involved in the phage infection process in complex systems such as milk and dairy products still need to be clarified. It is well known that receptors of the bacterial cell wall play a key role in the infection process. In the present paper, several criteria were proposed regarding the way in which the interactions between the phage-host system and food may occur and how these interactions could affect the treatment effectiveness. According to the current knowledge in the field, we identify two key interfering principles, namely, food structure and milk compounds with binding or bioactive capacity. Food structure is related to phage diffusion, and gel dairy products are the main foods that limit the encounter between phages and bacteria. Milk compounds, such as proteins, lipids, carbohydrates and bioactive compounds can compete with binding sites in phage-host systems, leading to a decrease in treatment effectiveness. •Food matrix plays a role in phage treatment.•Dairy liquid foods are suitable for phage treatment.•Phage-host system interaction is limited in dairy gels.•Antiphage compounds from milk limit the treatment effectiveness.•Protein, lipids and carbohydrates compete with binding sites between phage and host.