Detection and determination of ochratoxin A in grape products

Abstract

Ochratoxin A is a mycotoxin often found in grapes and grape products. Since it was first reported in wines approximately 10 years ago, several developments have been reported in its analysis from grapes and their derived products. Methods for qualitative, semi-quantitative and quantitative analyses have been developed in different formats. Most of these methods involve five main stages: sampling, sample preparation, extraction, clean-up and quantification. Sampling and sample preparation are two of the most critical stages, since the material portion taken to the laboratory for analysis should represent as accurately as possible the whole lot. The design of subsequent stages will be very dependent on the measurement (separation, detection and quantification). The extraction stage aims at solubilizing the mycotoxin in an appropriate solvent, and – depending on the measurement method – various clean-up strategies are available. Highly specific and selective measurement will require less extensive clean-up and vice versa. Most of the methods rely on the general guidelines for sampling, an extraction with an aqueous-based solvent, clean-up with immunoaffinity columns and quantification by a chromatographic method coupled with fluorescence or mass detection. In this chapter, the recent developments in ochratoxin A detection are presented and the most representative methods for the analyses of grapes, dried vine fruits and wine are presented and discussed.