RESUMO
The aim of this manuscript was to validate and apply an analytical methodology for the simultaneous determination of 34 mycotoxins in cocoa. The extraction method used in the tests was a liquid-liquid partition by NaCl addition with a freezing step followed by quantification using LC-MS/MS. The results were discussed based on national and international directives for food contaminants. The recoveries and precision were adequate, except for the mycotoxins ionized with the ammonium adduct (NH4+), E-cristinine and ß-ZOL. This result directly influenced the measurement uncertainty of these mycotoxins, because the precision and the correction factor of the recovery were the factors with the greatest impact on the uncertainty of the method. The evaluation of the matrix effect showed considerable signal suppression for 53 % of the evaluated mycotoxins. Nevertheless, the mycotoxins exhibited relatively low quantification limits, with values between 1 and 75 µg kg-1. The validated methodology was applied to 15 cocoa samples collected in warehouses in Brazil. Positive results were found for all the evaluated samples, in which nine toxins were detected out of the 34 investigated.
Assuntos
Cacau , Micotoxinas , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Micotoxinas/análise , Espectrometria de Massas em Tandem/métodos , IncertezaRESUMO
In the present study, the occurrence of aflatoxins (AFs) and ochratoxin A (OTA) was evaluated in 123 samples of cocoa beans produced in five Brazilian states. The presence of these mycotoxins was determined by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) after immunoaffinity column clean-up. The mean level of total AFs in cocoa beans samples was 5.7 µg.kg-1. Four (3.3%) samples exceeded the maximum limit of 10 µg.kg-1 established by the Brazilian legislation for total AFs. The mean level of OTA contamination was 1.2 µg.kg-1, and none of the samples exceeded the maximum limit established by the Brazilian legislation. The co-occurrence of AFs and OTA was observed in 4.9% of the samples. The results of the present study demonstrated that, in relation to the levels of AFs and OTA established by the Brazilian legislation, most samples of cocoa beans analyzed are safe for consumption. This is the first report on the occurrence and levels of AFs and OTA in cocoa beans from the five main Brazilian states producing cocoa. The data in this study provide important information for farmers, traders, industry, consumers and law enforcement agencies.