• OTA; Ocratossina A; Cromatografia; HPLC; MISPE.

Abstract

Ochratoxin A (OTA) is a secondary toxic metabolite produced by Aspergillus or Penicillium species, which can contaminate various crops. The International Agency for Research on Cancer (IARC) classified OTA as a group 2B possible human carcinogen. The aims of the present thesis were 1) to develop and validate new extraction/purification methods for OTA determination in wild boar tissues and 2) to assess OTA concentrations in tissues of wild boar (Sus scrofa L.) from Tuscany (Italy). Two analytical methods for OTA extraction/purification from wild boars tissues (muscle, liver and kidney) coupled to high-performance liquid chromatography with a fluorescence detector (HPLC-FLD) have been developed and validated according to CE 657/2002.
First we have developed a quantitative HPLC-FLD method based on enzymatic digestion (ED) followed by a chromatographic analysis with a single ethylacetate purification step for the detection of OTA in pig tissues. The second method consisted in the above ED method followed by a molecular imprinted solid phase extraction (MISPE) purification step. Both methods were validated taking into account the currently permitted limit of 1 μg/kg OTA in pork meat and derived products in Italy. The recovery was higher than 90%. Intra- and inter-day repeatability expressed as RSD were less than 7%. The LOD and LOQ were 0.001 and 0.002 μg/kg, respectively. Over a period of 2 years, samples of muscle, liver, and kidney from 48 wild boars were collected and concentrations of OTA were determined by (ED) coupled to high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The highest concentrations of OTA were found in the kidneys of the 48 wild boars analyzed. No difference in concentrations was found based on years of collection and sex while a significantly higher OTA concentration was found in the kidney of the young wild boars with respect to the adult one. Monitoring the quality of meat destined for transformation is a priority in order to decrease the possibility of toxin carry-over to humans. The present study showed that contamination of wild boar meat products by OTA represents a potential emerging source of OTA.