Análise de patulina e fungicidas em maçãs e sua degradação por campo elétrico contínuo

Abstract

Apple is the second most consumed fruit in the world and presents important economic and nutritional roles. Its cultivation is susceptible to attack by fungi, among which species capable of synthesizing mycotoxins, such as patulin. An alternative to minimize contamination by mycotoxins is the control of fungi using fungicides, which in turn can also present toxicity to humans. The objective of this study was to use chromatographic methods coupled to mass spectrometry to detect and quantify the fungicides: captan, carbendazim, chlorothalonil, epoxyconazole, pyraclostrobin, tebuconazole, tetraconazole, and trifloxystrobin and the mycotoxin patulin in apples, and to evaluate the potential of applying a continuous low intensity electric field for degradation of patulin and the fungicide pyraclostrobin. Patulin and fungicides were extracted from apples using a QuEChERS method. The method of analysis of patulin by gas chromatography coupled to mass spectrometry (GC-MS) showed recovery ranging from 91.8% to 114.8% and limits of detection and quantification of 0.61 ηg mL-1 and 3.57 ηg mL-1, respectively. The fungicides: carbendazim, epoxiconazole, pyraclostrobin, tebuconazole, tetraconazole, and trifloxystrobin, were analyzed by high performance liquid chromatography coupled to mass spectrometry (HPLC-MS-ESI-QToF-MS). The method showed recovery ranging from 94.5% to 100.4% and limits of detection and quantification that ranged from0.07 g mL-1to1.60 ηg mL-1, and from 0.21 ηg mL-1 to 4.85 ηg mL-1, respectively. Relative standard deviations for all methods were below 5% and coefficients of determination of analytical curves were above 0.99%. Seventy seven percent of apples and apple products marketed in Pelotas –RS analyzed, presented fungicide residue in quantities below the residue limits established by the National Health Surveillance Agency (ANVISA) and 10% showed the presence of fungicide not authorized for the crop. The application of continuous electric fields showed potential for degradation of patulin and residues of pyraclostrobin, presenting a degradation of up to 76% for patulin, and up to 64% for pyraclostrobin. The mathematical model established for the process of degradation of patulin presented a determination coefficient of 82% and by response surface analysis it was possible to observe that at the greatest potential tested (2.6 V) it is possible to obtain a maximized degradation in all pH conditions evaluated.