Aflatoxins and ochratoxin A in dried chestnuts and chestnut flour produced in Italy

Abstract

The occurrence of aflatoxins and ochratoxin A in chestnut products made in Italy was surveyed. Thirty-seven samples of chestnut flour and fourteen of dried chestnuts were collected from retail outlets located in northern Italy. After extraction and purification through an immunoaffinity column, aflatoxins and ochratoxin A were analysed using both HPLC-FLD and HPLC-MS/MS. The mycotoxin contamination found in this survey was widespread and remarkable. As regards aflatoxins, the incidence of aflatoxin B1 was 62.2 and 21.4% in chestnut flour and dried chestnuts, respectively; in the same products, the percentage of samples exceeding the value of 2.0 μg kg−1 for aflatoxin B1 (maximum limit fixed by EC Regulation 165/2010 in dried fruits) was 24.3% and 7.1%. A widespread and high incidence of AFG1 was also found (40.5%). The maximum values for aflatoxin B1 and total aflatoxins were 67.88 and 188.78 μg kg−1, respectively (chestnut flour sample). Ochratoxin A occurred in all samples, showing very high values (mean 12.38 and 13.63 μg kg−1 for chestnut flour and dried chestnuts, respectively); the percentages of samples exceeding the limit of 10 μg kg−1 (EU limits for dried vine fruit) were 64.9 and 42.8% for chestnut flour and dried chestnuts, respectively. The maximum value was 65.84 μg kg−1 (dried chestnut sample).