Incidence of toxigenic fungi and ochratoxin A in dried fruits sold in Brazil

Abstract

A total of 117 dried fruit samples (black sultanas, white sultanas, dates, dried plums, dried figs and apricots) from different origins were analysed both for toxigenic fungi and for the presence of ochratoxin A. Amongst the fungi found, Aspergillus niger was predominant, with 406 isolates, of which 15% were ochratoxin A producers. They were followed by A. ochraceus, with 15 isolates and 87% ochratoxigenics, and A. carbonarius, with only five isolates of which 60% were ochratoxin A producers. The average infection rates for A. niger in black sultanas, plums, figs, dates and white sultanas were 22.0, 8.0, 4.0, 1.5 and 0.5%, respectively. The apricot samples were not contaminated by any fungi or ochratoxin A. Black sultana and dried figs contained the highest contamination with ochratoxin A, with 33 and 26.3% of the samples containing more than 5 µg kg⁻¹ respectively, while all the white sultanas, dates and plums had no sample that exceeded this limit.

Keywords:

• Dried fruits
• toxigenic fungi
• ochratoxin A

Acknowledgements

The authors thank the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP — Proc no. 01/02830-3) for financial support and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) for an MSc grant.