Aflatoxins and Ochratoxin A in Red Paprika for Retail Sale in Spain: Occurrence and Evaluation of a Simultaneous Analytical Method

Aflatoxins are well-known mycotoxins produced mainly by two Aspergillus species particularly abundant in areas of the world with hot, humid climates. Aspergillus flavus, which is ubiquitous, produces B aflatoxins. A. parasiticus which produces both B and G aflatoxins, has more limited distribution. The next most studied mycotoxin is ochratoxin A. It belongs to a group of five produced by Penicillium verrucosum and by several species of Aspergillus, most notably A. ochraceus. Contamination of red pepper spice by aflatoxins and ochratoxin A may occur at any stage of production, from preharvest to drying and storage. Aflatoxins are the only mycotoxins with legal limits for spices in the European Union. A further limit for ochratoxin A is expected to be adopted soon. Thus, rapid simultaneous methods for quantifying the five mycotoxins are sought. Liquid extraction, immunoaffinity column cleanup and HPLC-FD with a wavelength programme were optimised for the analysis of the five mycotoxins in paprika, a complex fatty matrix. The limits of detection ranged from 0.3 to 0.6 μg/kg. Repeatability (RSDr) ranged from 7.9 to 13.4% and recoveries were between 61.4 and 77.8%, in both cases at the lower spike level. Aflatoxins, when found, were far below the two legal limits, of 5 μg/kg for aflatoxin B1 and 10 μg/kg for total aflatoxins. Ochratoxin A was more frequently found, with a mean of 11.8 μg/kg, and in a more varied range (SD 18.9 μg/kg). On attempting an automation of the precolumn derivatisation step the procedure proved unfeasible, but experience derived from this trial and from the general employment of this reaction enables us to make some comments on the possibilities and limitations of this procedure and on research for an alternative one.