Occurrence of ochratoxin A in sweet wines produced in Spain and other countries

Abstract

A survey for the presence of ochratoxin A (OTA) was undertaken from 2001 to 2005 in 188 samples of sweet wines produced in Spain and in 102 samples originating from other countries: France (n = 49), Austria (9), Chile (9), Portugal (9), Greece (6), Italy (5), Germany (3), Hungary (2), Slovenia (2), Switzerland (2), Canada (1), Japan (1), New Zealand (1), Ukraine (1), South Africa (1) and the USA (1). The analytical method was based on immunoaffinity chromatography clean-up and high-performance liquid chromatography (HPLC) with fluorescence detection. The limit of detection (defined as a signal–noise ratio = 3) was estimated to be 0.01 µg l⁻¹. The limit of quantification (0.02 µg l⁻¹) was checked as being the lowest measurable concentration. OTA was detected in 281 out of 290 samples analysed (96.9% positive) at concentrations ranging from 0.01 to 4.63 µg l⁻¹. The overall mean and median levels were estimated to be 0.50 and 0.14 µg l⁻¹, respectively. In Spanish sweet wines OTA was found in 99% of the samples, with mean and median values of 0.65 and 0.19 µg l⁻¹, respectively. The mean value obtained in this study for OTA in the Spanish sweet wines would result in an intake of about 37.5 and 3.2 ng day⁻¹ of OTA for regular consumers and for the overall population, respectively. These figures represent a minor contribution to the provisional tolerable weekly intake (PTWI) or TWI established by the Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority: 3.8 and 3.1% for regular consumers; and 0.4 and 0.3% for the whole adult population, respectively.

Keywords:

• Ochratoxin A
• sweet wine
• occurrence
• analysis
• risk assessment
• dietary intake

Acknowledgements

The authors are grateful to the Spanish Food Safety Agency, which supported the study. They also wish to thank Ladislao Montiel, winemaker of the winery ‘Camilo Castilla’, Navarra, Spain, for providing technical advice and knowledge on sweet wines. Finally, they are especially grateful to Ir. H. Van Egmond for his kind review of the manuscript.