Oregano essential oil as an alternative antimicrobial for the control of Listeria monocytogenes and Salmonella in Turkey mortadella during refrigerated storage.

Abstract

Given consumer preference for “natural” and clean-labeled products, validating new ingredients that achieve the same antimicrobial, antioxidant, or other functions as those being replaced is critical. In this study, the antimicrobial activity of free and encapsulated oregano essential oil (OEO) utilized as ingredients in the formulation of turkey mortadella was independently tested against cocktails of Listeria monocytogenes and Salmonella spp. throughout 13 days of storage at 10 °C. Their activity was compared to potassium lactate (PL, 1 g/100 g or 2 g/100 g) and potassium sorbate (PS, 0.1 g/100 g). It was found that 0.5 g/100 g free OEO was more effective than PS and did not allow more than 2 log-cycles growth of L. monocytogenes. Encapsulation of 0.25 g/100 g OEO by complex coacervation or emulsification techniques did not enhance the antimicrobial efficiency of the oil. Combining 0.05 g/100 g of encapsulated OEO with 1.0 g/100 g PL effectively controlled L. monocytogenes growth but was no more effective than the formulation with 1.0 g/100 g PL. Results highlight the importance of testing potential alternative antimicrobials in specific foods and of considering the cost-benefit of encapsulation approaches which need further research as potential concealers of undesired sensory attributes.

Keywords

• Foodborne pathogen
• Oregano essential oil
• Antimicrobial
• RTE poultry meat
• Encapsulation