【作者】 李云成；

【导师】 焦必宁；

【作者基本信息】 西南大学 ， 农产品加工及贮藏工程， 2012， 硕士

【摘要】 柑桔是世界第一大水果,柑桔及其制品种类繁多,柑桔汁、皮渣饲料和柑桔精油作为最主要的柑桔加工品,为社会带来了不菲的经济价值。柑桔及其制品的质量安全不仅关系到人类的健康,还对产业的良好发展起着重要作用。农药残留是危害柑桔及其制品质量安全的最主要因素之一,也是食品质量安全最重要的危害因素。研究农药残留在加工过程中的残留动态,不仅可以为优化加工工艺提供依据,更重要的是为食品安全风险评估提供数据支撑。本试验首先建立了吡虫啉、多菌灵、阿维菌素、氯氰菊酯、咪鲜胺在不同柑桔基质中的QuEChERS结合UPLC-MS/MS的检测方法,以及炔螨特的QuEChERS结合GC-MS/MS的检测方法。结果显示：吡虫啉等5种农药在不同柑桔基质中的加标回收率介于70.9%到117%,相对标准偏差低于21%,炔螨特在不同柑桔基质中的加标回收率介于70.4%到102.3%,相对标准偏差低于13%。所有农药的最低检测限介于0.03μg kg-1到3μg kg-1，表明该方法的准确度、精确度和灵敏度均符合农药残留定量分析要求。本试验以北碚447锦橙为研究对象,采用田间施药和采后浸药的方式强化农药在原料果中的残留。吡虫啉等5种农药的田间施药浓度为5倍推荐最高剂量,总共施药3次,施药的间隔期为7天,最后一次施药24h后采样,所采样品立即送达车间进行加工。咪鲜胺的浸药浓度为5倍推荐最高剂量,浸药后沥干放置3天后进行加工。加工按照橙汁商业化加工过程进行,并在不同取样点处取样,每种农药的鲜果分三个加工批次,每个批次的样品分三个检测重复。其主要研究结果如下(1)农药主要残留于甜橙的果皮中.果肉中的农药残留水平相对较低,未清洗全果的果肉中吡虫啉等5种农药的残留水平占全果的4.4%-17.9%,咪鲜胺占65.4%。果皮中各农药残留水平比果肉高出1.16-4.44倍。(2)橙汁加工过程中的清洗能去除一部分农药残留,其加工因子为0.146-0.675；初榨果汁中的各农药残留水平显著降低,加工因子为0.04-0.111；精滤能进一步降低农药残留的水平,但降低幅度不大。经杀菌后的NFC橙汁中各农药残留水平均低于原料果的4%,但相对于杀菌前,毗虫啉、多菌灵和阿维菌素的残留水平未降低,而氯氰菊酯、咪鲜胺和炔螨特的残留水平降低;浓缩过程使吡虫啉、多菌灵和阿维菌素的残留水平较浓缩前有所上升,却使氯氰菊酯、咪鲜胺和炔螨特的残留水平下降,但浓缩果汁中各农药的残留水平相对原料果很低,其加工因子为0,002-0.071。(3)榨汁过程使一部分残留农药分布于皮渣中,皮渣的吡虫啉等残留的加工因子为0.459-0.947,炔螨特加工因子为1.282；精油的离心分离过程使毗虫啉和多菌灵的残留水平显著降低,加工因子分别为0.016和0.038,但使阿维菌素、氯氰菊酯、咪鲜胺和炔螨特的残留发生富集作用,加工因子分别为28.160、5.621、5.232和18.495。本试验还利用国内理论最大膳食摄入评估(NTMDI)和国内日摄入估计(NEDI)法对柑桔鲜果以及橙汁中各农药的膳食暴露风险进行评估,研究结果如下：(1)柑桔鲜果中各农药经NTMDI和NEDI评估的风险指数均小于100%,即所有农药的膳食摄入风险在可接受范围。随着人群年龄的增加,由于体重的增长,各农药的膳食暴露量降低。男女性别差异造成身体发育和饮食习惯差别,故同年龄段的男女对农药的暴露水平不同,总体水平为男性的暴露风险低于女性。(2)由于未考虑加工过程对农药残留造成的影响,故采用NTMDI模式评估的风险指数比考虑了加工影响的NEDI模式的风险指数高。采用NEDI模式对清洗和未清洗鲜果进行评估,结果显示,清洗后其暴露风险指数得到不同程度降低。(3)利用NEDI模式对橙汁中各农药的暴露风险进行评估。结果显示,经一系列加工后的橙汁中各农药对人群的暴露风险极小,吡虫啉等5种农药的风险指数均小于0.0104%,咪鲜胺的风险指数仅为0.144%。更多还原

【Abstract】 Citrus is considered to be one of the major fruit crops produced in the world, citrus and its products, including citrus juice, pomaces feeds and essencial oils, are so large that brings about much economic values for the society. The quality and safety of citrus and its products are not only related to humans’health, but also related to the development of citrus industry. Pesticide residues are one of the main hazards of the citrus quality and safety, as well as one of the most important hazards of food. Good knowledge of the effects of food processing on pesticide residues can provide the basis for the optimization of processing technology. More importantly, it is necessary to properly assess human dietary exposure.In this experiment, firstly, the analysis methods of UPLC-MS/MS combined with the QuEChERS for determination imidacloprid, carbendazim, abamectin, cypermethrin, prochloraz, and GC-MS/MS combined with the QuEChERS for determination propargite were developed. The results indicated that the mean recoveries and Relative Standard Deviation (RSD) values (n=6) are ranging from 70.9%to 117%for imidacloprid, carbendazim, abamectin, cypermethrin, prochloraz with RSD lower than 21%. the recoveries of propargite were ranging from 70.4%to 102.3%with RSD (n=5) lower than 13%. The limits of detection (LODs) of all the pesticides were varied from 0.03 ug kg-1 to 3 ug kg-1. In a word, the testing methods were able to completely satisfy requirements of detecting pesticide residues.The Beibei 447 sweet oranges were selected as the RAC samples for this experiment. Field trials for imidacloprid. carbendazim, abamectin, cypermethrin and propargite were carried out to guarantee sufficient residue levels in RAC samples for further processing studies, The trees were sprayed with 5-fold the concentration of the maximum recommended dosage solutions, for a total of three sprayings with an interval of 7 days between sprayings. The fruits were picked 24 hours after the last spraying, and were sent immediately to the workshop for processing. The orange fruits were soaked with 5-fold the concentration of the maximum recommended dosage solutions of prochloraz, then drained and stored for three days before processing. All fruits sprayed with each pesticide were divided into three batches; each batch of samples was divided into three detection replicates. The main results were list as follows:(1) The pesticide residues were mainly distributed in orange peels, about 4.4%-17.9%of total relative pesticide residues were contained in the unwashed orange pulps. However, prochloraz was an exception, with 65.4%of the total residues present in the pulps of unwashed oranges. The residue levels of all the pesticides in peels were 1.16-4.44 times higher than pulps.(2) The residues distributed in the face of peels could be partially removed by washing during commercial processing of orange juice, the processing factor of juicing was ranged from 0.146 to 0.675; low residue levels were observed in squeezed juice, and the processing factor was ranged from 0.044 to 0.111, filtrating could further reduce all the pesticide residues. There was only 0.55-3.14%of the total relative pesticide residues were contained in NFC juice, the residue level of cypermethrin, and prochloraz in NFC juice were decreased comparing with the filtrated juice samples, but the residue level of abamectin was unchanged and the concentration of imidacloprid and carbendazim were increased. After concentration, the residue levels of cypermethrin and prochloraz were reduced, but the levels of imidacloprid, carbendazim and abamectin were increased. However, the residue levels in concentrated juice were also very low, and the processing factors of concentrated juice were ranged from 0.002 to 0.071. (3) Some pesticide residues had been translocated to pomace during juicing, and the processing factor of pomace was ranged from 0.007-1.282. The residue levels of imidacloprid and carbendazim in orange oil were reduced and the processing factor was 0.016 and 0.038. respectively, but the other 3 pesticides were concentrated in orange oil, and the concentrated factor of abamectin, prochloraz and cypermethrin was 28.160,5.232 and 5.621. respectively.The National Theoretical Maximum Daily Intake (NTMDI) and National Estimated Daily Intake (NEDI) were applied to assess the dietary exposure of pesticide residues in orange fruits and juice, the results were list as follows:(1) The risk index of all the pesticide residues in citrus fruits were less than 100%after assessment by NTMDI and NEDI, that is to say the risk is accepted. The exposure risk was reduced along with the age increasing due to the change of body weight and dietary habit. The dietary exposure of females is higher than males because of the gender discrepancy that caused by the difference of body growth and dietary habit.(2) Owing to the processing factor had not been considered, the results assessed by NTMDI is higher than NEDI, which is fully considered the effect of processing during assessment. What’s more, the risk index assessed by NEDI of the pulps of washed whole fruits is lower than unwashed whole fruits.(3) The risk of pesticide residues in orange juice is assessed by NEDI; the results indicated that the risk in orange juice is very low; the risk index of prochloraz was 0.144%, and the other 5 pesticides risks were lower than 0.0104%.更多还原