Microencapsulated oregano and cinnamon essential oils as a natural alternative to reduce Listeria monocytogenes in Italian salami

Abstract

Meat products are classified as perishable foods and have favourable conditions for the multiplication of microorganisms such as Listeria monocytogenes, an important pathogen associated with ready-to-eat foods. Natural compounds are used for food preservation combined with encapsulation techniques to improve efficiency. This study evaluated the anti-Listeria potential of isolated and combined microencapsulated oregano (OEO) and cinnamon (CEO) essential oils in Italian salami. Different combination ratios of OEO and CEO were tested and 50:50 ratio (OEO:CEO) was encapsulated using sodium alginate. The microcapsules were evaluated for encapsulation efficiency (EE), morphology and action against L. monocytogenes in a meat matrix. Empty microcapsules and 50/50 combined EO were incorporated into the Italian salami to evaluate the physicochemical, microbiological and sensory properties. All combinations of EO showed L. monocytogenes inhibition zone and CIM with 1:16 dilution. The microencapsulated EO had 98.36% encapsulation efficiency. Using 2% microcapsule had a significant reduction of L. monocytogenes from the control. Even though the panellists mentioned the sandy attribute in the CATA, the salami with EO microcapsules texture did not differ from the control. Although the essential oils had high encapsulation efficiency, the smell and flavour of cinnamon and oregano interfered negatively with the sensory analysis. However, the encapsulation of the combined essential oils (50/50) significantly reduced L. monocytogenes in Italian salami.