A review of the structure, mechanism, and application of bacteriocins in foods as natural preservatives

In recent years, the incidence of foodborne illnesses has caused considerable concern among the population. Despite advanced mechanisms in health and inspection during food production, microorganisms are potential hazards during food processing, packaging, transportation, storage, and distribution. To reduce the economic loss and life-threatening diseases, and also diminish the adverse effects of chemical preservatives on foods and the increased resistance of microorganisms to antibiotics, the application of natural antimicrobial compounds that have detrimental and inhibitory effects on the pathogenic agents has been considered by researchers. Bacteriocins produced by lactic acid bacteria such as nisin, lacticin 3147, pediocin PA-1, pediocin AcH, and enterocin A and B are natural antimicrobial additives. Researchers face limitations when using bacteriocins such as inappropriate distribution in the food matrix, lack of inhibition in gram-negative bacteria and yeast, inefficiency in the neutral and alkaline pH range, and inactivation at high temperatures. To address these problems, processed bacteriocins such as microencapsulated nisin are used instead of free nisin. Also, bacteriocins are applied in combination with other processes such as active packaging, high hydrostatic pressures, pulsed electric fields, gentle heat treatments, and lactoperoxidase system. In this study, first, the bacteriocins in terms of their structure and mechanism of action are reviewed and then the use of bacteriocins in foods as natural preservatives is discussed.