Plant extracts as biopreservatives against Penicillium nordicum in dry-cured sausages

Abstract

One of the major hazards in cured meat is the ochratoxin A (OTA) accumulation, being the main producer Penicillum nordicum. Plant extracts can be used as biopreservative agents to its minimisation. The aim of this work was to evaluate the activity of essential oils from rosemary (REO), thyme (TEO) and oregano (OEO), and an acorn extract (AE) against three P. nordicum strains by analysing their inhibitory capacity on their growth and OTA biosynthesis in a dry-cured sausage-based agar. When evaluating their effect on the mould growth, the essential oils showed different antifungal activity, being concentration dependent. Concretely, the TEO and OEO activity was greater than that of REO, with a loss of activity throughout the incubation. As incubation time progressed, the plant extract ability to reduce the OTA content decreased. Additionally, differences at strain level were noticed depending on the plant extract, since some of them were able to trigger an overproduction of OTA. REO 500 μL/mL and OEO 50 μL/mL reduced the OTA production up to 93 and 98%, respectively, showing the best outcomes to be further explored as effective strategy to control the presence of OTA due to P. nordicum in drycured sausages.