枸杞子作为著名药食同源物质，随着其种植面积不断增加，病虫害现象逐年加重，致使农药使用种类增多和剂量加大，造成了枸杞子农药残留现象严重。有关枸杞子药材的农药残留检测方法、农药残留限定标准等已有大量报道，但对枸杞子提取物农药残留检测及加工过程中的农药残留转移行为尚未见报道。因此，探究枸杞子不同提取加工工艺过程中的农药残留转移行为，以及对不同工艺制备产品进行膳食暴露风险评估，具有重要现实意义。

本论文首先建立了枸杞子药材、提取液及提取物中43种高频检出残留农药的超快速液相色谱-串联质谱（UFLC-MS/MS）检测方法。运用乙腈浸提、分散固相萃取等技术净化样品，乙腈-水梯度洗脱，计划多反应监测（Schedule MRM）质谱扫描模式检测。方法学验证结果表明，不同基质中43种农药在0.0005-0.2 mg/kg的范围内线性关系良好，相关系数r>0.99，精密度RSD均小于6%（杀螟硫磷15%），重复性RSD均小于10%，三种添加水平下的回收率范围在75%-115%之间（多菌灵63%-80%），符合农药残留检测要求。该方法简便、快捷，适用于枸杞子及提取加工过程各产物的农药残留检测。

利用建立的UFLC-MS/MS分析方法，对43种农药强化枸杞子的水提物、醇提物及水提醇沉物加工过程中的农药残留转移行为进行了研究。结果表明：农药强化枸杞子的水提醇沉物（粗多糖）、水提物和醇提物的农残量与强化枸杞子比较，分别降低了98.17%、66.38%、41.82%，说明提取加工对农残具有明显的脱除作用。加工因子计算表明水提物为0.49，醇提物为0.80，说明水提取对农残脱除效果更好；水提液在乙醇沉淀后，残留农药几乎完全转移至醇清液中，在沉淀物中农残量极低；浓缩和干燥过程对农残的加工因子影响较小。农药残留的转移行为不仅与农药的理化性质有关，还与提取溶剂、加工过程有关。良好的加工工艺，会使农药残留水平大幅降低。

根据前期研究及文献查阅，以易转移、易残留及高频检出为依据，选择啶虫脒、吡虫啉、克百威及3-羟基克百威4种农药制备农药强化枸杞子，进一步研究不同加工工艺农药残留的转移行为。茶冲泡研究表明，强化枸杞子残留农药的溶出呈Weibull函数分布特征，每次冲泡的转移量大约为残渣中残留量的1/3；加盖冲泡时残留农药在茶汤中的浸出量更高。因此，采用合理的冲泡方式，可以减少枸杞子中残留农药的摄入量。制备加工过程农药残留转移研究表明：与前期实验结果比较，加工条件相同时，同一种农药的转移行为趋势相同，说明提取加工时各残留农药之间的相互影响较小。

采用点评估模型对不同食品安全等级的枸杞子药材及其水提取物、模拟农药强化后的枸杞子及各提取物的农药残留膳食暴露风险进行了评估。结果表明有机、绿色、无公害、普通等不同等级的枸杞子干果及相应的提取物长期膳食风险和急性膳食风险分别在0.4%-4.9%和0.1%-21.5%范围。可以看出，不同等级的枸杞无论是枸杞干果还是提取物，膳食都是安全的。对43种农药强化枸杞子及其水提物、醇提物及水提醇沉物的农药残留急性和长期膳食风险评估结果分别为：403.8%、156.0%、274.7%、6.0% 和 548.6%、121.9%、397.6%、3.3%。同样，对啶虫脒、吡虫啉、克百威及3-羟基克百威4种农药模拟强化的枸杞子及水提物、醇提物及水提醇沉物、水提醇沉上清物的急性和长期膳食风险评估结果分别为：103.7%、59.5%、90.5%、8.1%、43.3%和504.8%、287.5%、439.8%、38.8%、209.5%。可以看出，加工过程可以显著降低农药残留的膳食风险。即使43种农药超限量标准10倍的枸杞子，如果采用良好的加工工艺，急性和长期膳食风险可以分别降低67倍和166倍，达到可接受的膳食风险水平。

本文的研究结果不仅为枸杞子的规范使用提供了科学的依据，同时也为其他花果类药食同源物质的应用提供参考。

Lycii Fructus is a famous medicinal and edible homologous material. With the increase of its planting area, its diseases and insect pests are gradually aggravated. So, the pesticides are widely used, resulting in the serious pesticide residues in wolfberry fruits. A lot of reports on detection methods and limit standards on pesticide residues of Lycii Fructus have been reported. However, the detection of pesticide residues in Fructus Lycii extract and the samples during processing have not been reported. Therefore, it is of great significance to explore the transfer behavior of pesticide residues in different processes of wolfberry, and to evaluate the risk of dietary exposure of products prepared by different processes.

Firstly, the UFLC-MS / MS method was established for the detection of 43 pesticide residues in fruits and various extracts of Lycium barbarum. The samples were purified by acetonitrile extraction and dispersive solid phase extraction, the mobile phase of chromatographic system was eluted by acetonitrile-water gradient, and the mass detected system was set by Schedule MRM mode. The results of method validation showed that there was a good linear relationship in the range of 0.0005-0.2 mg / kg, the correlation coefficient r > 0.99. The RSDs of precision were less than 6 % (parathion 15 %), and the RSDs of repeatability were less than 10 %. The recovery ranged was from 75 % to 115 % (carbendazim 63%--80 %). The method met the requirements of pesticide residue detection and is suitable for the detection in wolfberry fruits and its extracts.

Using the established UFLC-MS/MS analysis method, the pesticide residues were detected in the wolfberry intensified with 43 pesticides and its various extracts. The results showed the pesticide residues decreased 98.17%, 66.38% and 41.82%, respectively, in the sample using water extraction with alcohol precipitation, and the sample with water extraction, and the sample with ethanol extraction, as compared with the pesticide intensified fruits, which showed that the preparation has obvious removal effects on pesticide residues. Both processing factors of water extract and ethanol extract are 0.49 and 0.80, suggesting that water extraction is better for the removal of pesticide residues. After the water extraction with alcohol precipitation, the residual pesticides almost completely transferred to the alcohol supernatant, of which in the precipitation was very low. The concentration and drying had little effect on the processing factors. The transfer behavior of pesticide residues is not only related to their physical and chemical properties, but also related to the processing technology, which, will reduce the level of pesticide residues significantly with good processing method.

Based on our previous results and literature review，four pesticides (acetamiprid, imidacloprid, carbofuran and 3-hydroxycarbofuran) were chosen to prepare pesticide intensified wolfberry, which were used to research transfer behavior of pesticide residue in different processing. The study on tea brewing experiment showed that the dissolution of residual pesticides displayed Weibull distribution, the amount of each brewing was about 1/3 of the residual in the residue. The leaching amount of residual pesticides in tea soup with cover was higher than that without cover. Therefore, the intake of pesticide residue in wolfberry can be reduced by using reasonable brewing method. As compared with the previous experimental results, the transfer behavior of the same pesticide under the same preparation showed the same transfer trend, indicating that the interaction among the pesticides during processing was very small.

The point assessment model was used to assess the dietary exposure risks of various Lycii Fructus and their extracts. The assessment values of the long-term and acute dietary risks in the fruits of different grades (organic, green, pollution-free, common) of market wolfberry and their extracts were with the scopes of 0.4 - 4.9 % and 0.1- 21.5%, respectively, which can conclude that different grades of Lycii Fructus, whether dried fruit or extracts, are safe to eat. The assessments values of the long-term and acute dietary risks in 43 pesticides intensified wolfberry, as well as its extracts with water, ethanol, and water extraction with ethanol precipitate, were 403.8%, 156.0%, 274.7%, 6.0% and 548.6%, 121.9%, 397.6%, 3.3%, respectively. Meanwhile, the assessment results in 4 pesticides (acetamiprid, imidacloprid, carbofuran and 3-hydroxycarbofuran) intensified wolfberry, as well as its extracts were 103.7%, 59.5%, 90.5%, 8.1% and 504.8%, 287.5%, 439.8%, 38.8%, respectively. It can be seen that the processing can significantly reduce the dietary risk of pesticide residues. If good technology was used to process the wolfberry which intensified with 43 pesticides and exceeded 10 times the pesticide limit, the acute and long-term dietary risks can be reduced by 67 times and 166 times, respectively, and can reach the acceptable risk level of dietary.

This study not only provides a scientific basis for the normal use of Lycii Fructus, but also provides a reference for the application of other medicinal and edible homologous substances.