Este estudo comparou quatro procedimentos de extração para a determinação simultânea das micotoxinas citrinina e ocratoxina A em amostras de arroz. Os procedimentos de Soares e Rodriguez-Amaya, Tanaka e os métodos de extração QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) e por ultrassom foram comparados em termos de geração de resíduos, limite de detecção, limite de quantificação e recuperação simultânea de micotoxinas. O procedimento de Soares e Rodriguez-Amaya e a extração por ultrassom apresentaram as menores recuperações, 83 e 55% para a ocratoxina A (OTA) e 55 e 48% para citrinina (CIT), respectivamente. O procedimento de Tanaka e a extração QuEChERS tiveram recuperações de 98 e 105% para OTA e 64 e 78% para CIT, respectivamente. Este último permitiu a extração simultânea das duas micotoxinas com uma redução de até 25 vezes na quantidade de solventes.This study compared four extraction procedures for the simultaneous determination of mycotoxins ochratoxin A and citrinin in samples of rice. Soares and Rodriguez-Amaya and Tanaka procedures and the extraction methods QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and by ultrasound were compared in terms of residue generation, limit of detection, limit of quantification and simultaneous recovery of mycotoxins. Soares and Rodriguez-Amaya and the method by ultrasound presented the lowest recoveries, 83 and 55% for ochratoxin A (OTA) and 48 and 55% for citrinin (CIT), respectively. Tanaka procedure and QuEChERS method presented the highest recoveries, 98 and 105% for OTA and 64 and 78% for CIT, respectively. The latter enabled the simultaneous extraction of the two mycotoxins, with a reduction of up to 25 times of the amount of the involved solvent.Keywords: rice, occurrence, ochratoxin A, citrinin, extraction method
IntroductionFungi produce a large variety of toxic secondary metabolites called mycotoxins.1 These compounds comprise several chemical structures including some relatively simple ones, 1 which occur in mycelium of filamentous fungi, normally after a period of balanced growth followed by stress conditions. 2,3 Aspergillus, Penicillium and Fusarium are among the fungal genera that occur in food and that have toxigenic species, such as Aspergillus ochraceus and Penicillium citrinum, the main producers of ochratoxin A and citrinin, respectively. 4,5 Ochratoxin A (OTA) (N-{[(3R)-5-chloro-8-hydroxy-3-methyl-1-oxo-3, 4-dihydro-1H-isochromen-7-yl] carbonyl}-L-phenylalanine, Figure 1) is classified by the International Agency for Research on Cancer (IARC from World Health Organization (WHO)) as a probably carcinogenic agent for humans (Group 2B, IARC).6 It has been also correlated to the Balkan endemic nephropathy (BEN). 7 Its presence was detected in many stored and dry foods, 8,9 such as corn, wheat, oats, beans, nuts, peanuts, rice, barley, sorghum, cotton seed, coffee beans, cocoa and spices. [10][11][12][13] Citrinin (CIT) [(3R,4S)-8-hydroxy-3,4,5-trimethyl-6-oxo-4,6-dihydro-3H-isochromene-7-carboxylic acid, The adverse effects cau...