Occurrence of aflatoxin B₁ and ochratoxin A in dried vine fruits from Greek market

Abstract

Twenty-six samples of dried vine fruits from Athens and Thebes (Central Greece) market were simultaneously extracted and cleaned up by immunoaffinity columns and analysed for aflatoxin B₁ (AFB₁) and ochratoxin A (OTA). A combination of ELISA and HPLC methods was applied for the determination of AFB₁. Recovery was 97.6%, RSD 6.46%, while the limit of detection (LOD) and limit of quantification (LOQ) were 0.05 μg kg⁻¹ and 0.09 μg kg⁻¹, respectively. OTA concentrations were only estimated by ELISA. Results revealed the presence of AFB₁ in 23% of the samples (mean 1.4 μg AFB₁ kg⁻¹), but none exceeded the EU limit (2 μg AFB₁ kg⁻¹). However, OTA was detected in 100% of the samples (mean 47.2 μg OTA kg⁻¹). Six samples were found to be contaminated at high levels (median 120.6 μg OTA kg⁻¹) and 18 exceeded the EU limit (10 μg OTA kg⁻¹).

Keywords:

• aflatoxin B₁
• ochratoxin A
• HPLC
• ELISA
• dried vine fruits

Acknowledgement

The authors thank the Laboratory of Food Microbiology and Biotechnology of Agricultural University of Athens and the director Professor G.J. Nychas (Department of Food Science and Technology) for providing the Multi-Mode Microplate Reader (Synergy™ HT, BioTek, Winooski, USA).