The authors are from the Ecotoxicology Laboratory of the Center for Nuclear Energy in Agriculture, Univ. of São Paulo-CENA/USP, Av. Centenário, 303, São Dimas, CEP 13416-000, Piracicaba, SP, Brazil.
J Food Sci. 2018 Oct;83(10):2669-2674. doi: 10.1111/1750-3841.14344. Epub 2018 Sep 14.
Gamma irradiation ( Co) in postharvest of common beans (Phaseolus vulgaris L.), has already proven beneficial, regarding the prolongation of shelf life and physical, chemical, and organoleptic aspects of grains. However, few prior studies have investigated the effect of gamma irradiation on the dissipation of pesticides in foods, especially insecticides in beans. This study aimed to evaluate the waste dissipation of two insecticides, imidacloprid and thiamethoxam, used in the cultivation of common bean, a variety of Carioca, using gamma irradiation. Ground bean samples were spiked each insecticide in the laboratory at 3, 4, and 5 mg/kg, and were then irradiated at 0, 1, and 2 kGy per irradiator with a Co source. Liquid chromatography-tandem mass spectrometry was used to quantify the insecticides. The irradiation promoted dissipation of thiamethoxam at 1 and 2 kGy doses, with the highest dissipation verified at 2 kGy. In general, at this higher dose of irradiation the reduction dissipation of thiamethoxam was 66% of the mean value found in the treatment without irradiation and ∼44% relative to the 1 kGy dose. Conversely, imidacloprid showed no effect of irradiation on waste dissipation, except in the treatment of 5 mg/kg at 2 kGy dose. From the results, it was concluded that the gamma irradiation might have applicability in dissipating thiamethoxam in real bean samples.
Pesticide residues remaining from bean cultivation, sensitive to optimal doses of gamma irradiation, can be transformed into other less harmful or nonharmful substances, increasing the quality of the beans before the food arrives at the consumer's table. Irradiation of the grains after harvest also eliminates the need for application of other pesticides to preserve the grains during storage, as the technique is capable of eradicating deteriorating agents, such as microorganisms and insects.
伽马辐照（Co）已被证明对延长豆类（菜豆属 Phaseolus vulgaris L.）的货架期以及谷物的物理、化学和感官方面有益。然而，很少有研究调查伽马辐照对食品中农药（尤其是豆类杀虫剂）消解的影响。本研究旨在评估两种杀虫剂——噻虫啉和噻虫嗪——在常规豆类（一种名为“Carioca”的品种）种植中的使用，通过伽马辐照来评估其在废物中的消解。将实验室中每一种杀虫剂在豆类样品中的含量分别设定为 3、4 和 5mg/kg，然后用 Co 源辐照器分别辐照 0、1 和 2kGy。使用液相色谱-串联质谱法来定量分析杀虫剂。辐照促进了噻虫嗪在 1 和 2kGy 剂量下的消解，在 2kGy 剂量下消解最高。一般来说，在更高剂量的辐照下，噻虫嗪的消解减少了 66%，与未辐照处理的平均值相比减少了约 44%，而与 1kGy 剂量相比则减少了 44%。相反，除了在 2kGy 剂量的 5mg/kg 处理中，噻虫啉的辐照消解没有效果。根据结果得出结论，伽马辐照可能适用于真实豆类样品中噻虫嗪的消解。
豆类种植过程中残留的农药，经伽马辐照最佳剂量处理后，可转化为其他毒性较低或无害的物质，从而提高豆类在到达消费者餐桌前的质量。在收获后对谷物进行辐照，也无需在储存期间应用其他农药来保存谷物，因为该技术能够消灭微生物和昆虫等变质剂。
