Gene Expression Analysis as a Method to Predict OTA Accumulation in Dry-Cured Meat Products

Abstract

Dry-cured meat products are frequently colonised by toxigenic Penicillium nordicum and Penicillium verrucosum throughout their ripening that can produce ochratoxin A (OTA). The predictive nature of the molecular analyses can be used to determine the risk of toxigenic species. For this reason, the objective of the present work was to analyse the temporal changes in the expression of the otapks and otanps genes by P. nordicum and P. verrucosum in relation to OTA production on slices of dry-fermented sausage salchichon and dry-cured ham. Gene expression was higher in P. nordicum than in P. verrucosum in both meat matrices. The otapks gene was overexpressed by both Penicillium species, especially in salchichon. OTA was only detected in inoculated salchichon regardless of the ochratoxigenic species used. The high significant correlation found between the early relative expression of the otapks gene and OTA production in salchichon leads to propose the relative gene expression of the otapks gene as a good indicator to predict OTA accumulation throughout the ripening of this product.