Antibacterial Effect of Nisin and Satureja edmondi Essential Oil Alone and In Combination with each other on Growth of Staphylococcus aureus in Hamburgers

Background and Nowadays consumers are cautious about foods and are more interested in foods that are less processed. This has led to significant approaches and replacing chemical preservatives in food products by different natural components. The essential oil of Satureja edmondi is used as a flavoring agent and known as a pharmaceutical plant because of its antimicrobial characteristics. Nisin is also an antibacterial peptide that is widely used to inhibit microbial growth in food products. The aim of this study was to investigate the inhibitory effects of Satureja edmondi individually and also in combination with bacteriocin nisin on the growth of Staphylococcus aureus in hamburgers.
Hamburger samples were inoculated with 5×103 CFU/g of S. aureus. Nisin treatment at 0.5% and essential oil of Satureja edmondi treatment at 0.01%, 0.02%, and 0.04% were prepared individually and in combination with nisin. The treated and control samples were packaged and kept at -12°C for 63 days. The samples were cultured on Baird–Parker Agar and the number of S. aureus were counted every seven days.
Compared to the control group, all treatments could significantly inhibit the growth of bacteria during the storage period. Simultaneous use of nisin and essential oil of Satureja edmondi increased bactericidal effects too.
Results revealed simultaneous use of 0.5% nisin and 0.04% essential oil of Satureja edmondi as the best treatment that could reduce the bacterial population. Also, sensory analysis revealed that 0.04% of the essential oil was not found pleasant by testers.