Abstract

Drying is one of the best food preservation methods, especially for grapes. This study aimed to determine the fate of pesticides after grapes are being subjected to different drying methods, namely, sun-, oven-, shade-, and alkaline-drying, which are employed in raisin production. Pesticide residues were determined by gas chromatography–tandem mass spectrometry (GC–MS/MS). Washing before drying decreased the diazinon, ethion, phosalone, penconazole, and hexaconazole levels in the grape samples by 52.04%, 6.75%, 9.99%, 56.54%, and 20.97%, respectively. In the raisins, the concentration of all the pesticide residues increased based on wet weight, and this result was due to dehydration; by contrast, the concentrations of the pesticides decreased based on dry weight. The sun-drying method demonstrated the greatest efficiency in residue removal wherein it decreased the diazinon, ethion, phosalone, penconazole, and hexaconazole levels by 76.65%, 68.40%, 69.55%, 72.74%, and 82.19% (dry weight), respectively. On the contrary, the shade-drying method demonstrated the least efficiency in reducing the residue levels (19.57%–42.55%). The evaluation of the processing results showed pesticide residue level in the raisins prepared using the investigated drying methods was higher than the maximum residual limits (MRL). This finding indicates that it is necessary to consider the pre-harvest interval in pesticide application in grape.

摘要

干燥是最好的食物保存方法之一，尤其是对葡萄而言。本研究旨在确定葡萄在葡萄干生产中采用的不同干燥方法（即日晒、烘箱、阴凉和碱性干燥）后农药的去向。通过气相色谱-串联质谱 (GC-MS/MS) 测定农药残留。干燥前洗涤使葡萄样品中的二嗪农、乙硫磷、膦酰菌胺、戊菌唑和己唑醇的含量分别降低了52.04%、6.75%、9.99%、56.54%和20.97%。在葡萄干中，所有农药残留的浓度都随着湿重的增加而增加，这是由于脱水造成的；相比之下，农药的浓度基于干重而降低。晒干法在去除残留物方面的效率最高，其中二嗪农、乙硫磷、膦酰菌胺、戊菌唑和己康唑的含量分别降低了 76.65%、68.40%、69.55%、72.74% 和 82.19%（干重）。相反，阴干法在降低残留水平方面的效率最低（19.57%~42.55%）。对加工结果的评估表明，使用所研究的干燥方法制备的葡萄干中的农药残留水平高于最大残留限量 (MRL)。这一发现表明，有必要考虑葡萄施药的收获前间隔。阴干法在降低残留水平方面的效率最低（19.57%–42.55%）。对加工结果的评估表明，使用所研究的干燥方法制备的葡萄干中的农药残留水平高于最大残留限量 (MRL)。这一发现表明，有必要考虑葡萄施药的收获前间隔。阴干法在降低残留水平方面的效率最低（19.57%–42.55%）。对加工结果的评估表明，使用所研究的干燥方法制备的葡萄干中的农药残留水平高于最大残留限量 (MRL)。这一发现表明，有必要考虑葡萄施药的收获前间隔。