农药残留风险评估在蔬菜水果和食用菌监测中的应用研究

为了解我国西北地区蔬菜水果和食用菌的质量安全情况及暴露风险,本试验从2018至2020年在我国甘肃省平凉市进行样品抽取,共测定2 435份蔬菜水果和食用菌样品中46种农药残留的含量.通过农药残留风险评估方法分析了 9类别蔬菜水果和食用菌中农药残留的分布和相关性,并对蔬菜和水果中农药残留情况进行了风险排序,以及暴露风险、...     

农药残留快速检测方法研究进展

在果蔬生产中,随着农药的大量和不合理使用,发展相应的农药残留检测技术已越来越受到社会的高度关注和重视,成为全球的焦点。该文概述了近年来果蔬农药残留快速检测方法的研究进展,主要包括酶抑制法、酶联免疫法、生物传感器法、近中红外光谱法、荧光光谱法、拉曼光谱法和核磁共振技术,详细介绍了上述方法的检测原理、研究现状及实际应用情况,分析了各方法的优缺点及研发难点,并对果蔬农药残留快速检测方法的发展趋势进行了展望。     

宁波市鄞州区农作物农药残留现状与控制对策

对鄞州区种植的稻谷、叶菜类、水果类、豆类、茄果类和块茎类农产品按月进行了411个批次抽样,按照国家相关规定对22个农药项目进行了检测。检测结果发现样本农药项目检出率为0.3%,农产品农药残留合格率97.82%,农药残留检出项目中88.89%是杀虫剂。超出农药残留标准的样本主要是5—10月的青菜,叶菜类超标样本率达到3.72%。农药残留超标样本在平原、滨海地区种植散户中有发现,而在山区各规模农户中均有发现。小学文化程度农户样本农药残留超标率高达4.50%,是大学文化程度农户样本农药残留超标率的6.16倍。为了降低鄞州区农作物农药残留率,提出5方面的控制对策。     

农药残留的表面增强拉曼光谱快速检测技术研究现状与展望

果蔬农药残留危害人类健康,施药后,农药分布于其表皮和内部组织,果蔬表面农药绝对残留量低、不均匀,直接光谱检测表征难,而表面增强拉曼散射(surface-enhanced Raman scattering,SERS)技术具有分子级检测精度,可以有效扩增信号,在实现微量物质检测方面优势明显。为此,论文综述了国内外表面增强拉曼散射技术的研究现状,特别是详细介绍了通过设计合理的表面增强拉曼基底结构,实现农药残留信号增强的主要技术手段和表面增强拉曼光谱信号分析方法。在此基础上,指出农药残留的表面增强拉曼检测技术研究中的前沿热点问题,探讨并展望了表面增强拉曼技术在农药残留快速检测方面的发展趋势。基于表面增强拉曼的农药高灵敏度、快速检测表征技术,将在农药违禁使用和农药残留超标监管中有广阔应用前景。     

Preformed Biomarkers Including Dialkylphosphates (DAPs) in Produce May Confound Biomonitoring in Pesticide Exposure and Risk Assessment

Low levels of pesticides and their metabolites/degradates occur in produce when pesticides are used in conventional or organic crop protection. Human dietary and nonoccupational urine biomonitoring studies may be confounded by preformed pesticide biomarkers in the diet. The extent of formation of putative urine biomarkers, including malathion specific (MMA, MDA; malathion mono- and diacids), organophosphorus generic (DMP, DMTP, DMDTP; dimethyl-, dimethylthio-, and dimethydithiophosphate), pyrethroid generic (3-PBA; 3-phenoxybenzoic acid), and captan-specific metabolites (THPI; tetrahydrophthalimide), was measured in produce samples containing the parent pesticide. Every produce sample of 19 types of fruits and vegetables contained biomarkers of potential human exposure. A total of 134 of 157 (85%) samples contained more molar equivalent biomarkers than parent pesticide. Malathion and fenpropathrin were sprayed (1 lb/A), and the time-dependent formation of pesticide biomarkers in strawberries was investigated under field conditions typical of commercial production in California. Malathion and fenpropathrin residues were always below established residue tolerances. Malathion, MMA, and MDA dissipated, while DMP, DMTP, and DMDTP increased, during a 20 day study period following the preharvest interval. The mole ratios of biomarkers/(malathion + malaoxon) were always greater than 1 and increased from day 4 to day 23 postapplication. Fenpropathrin and 3-PBA also dissipated in strawberries during each monitoring period. The mole ratios of 3-PBA/fenpropathrin were always less than 1 and decreased from day 4 to day 14. The absorption of pesticide biomarkers in produce and excretion in urine would falsely indicate consumer pesticide exposure if used to reconstruct dose for risk characterization.     

电解水技术在果蔬采后保鲜和商品化处理中的研究应用进展

电解水技术是果蔬采后保鲜和商品化处理的热点技术,该文对电解水抑制微生物、去除农药残留和提质延时保鲜3个方向开展技术总结和机理研究综述,并从电解水技术在采后果蔬的处理方式和专利申请方面对其应用性开展应用分析。总结发现,1）不同类型的电解水在果蔬采后保鲜领域研究不完善,酸性电解水较碱性电解水研究更丰富;2）酸性电解水是有效去除食源性致病细菌的农产品加工工程技术,但酸性电解水对果蔬腐烂真菌的抑制研究还不充分;3）电解水可以有效去除果蔬表面农药残留,在机磷农药上阐明了具体机理,对于有机氯、菊酯农药的降解研究不足;4）电解水处理可以有效提升果蔬的抗性、缓解果蔬低温贮藏冷害并抑制鲜切果蔬褐变;5）目前电解水应用方式较为单一,不适宜所有果蔬保鲜处理流程,技术专利申请较少。通过本文梳理归纳以期为电解水技术的工程技术应用拓展提供理论依据和参考。     

Thin layer chromatographic detection and indirect gas chromatographic determination of three carbamate pesticides.

Carbamate pesticide residues are extracted from vegetables and fruits with methylene chloride. The extracts are spotted on silica gel plates and the pesticides are detected by an enzymatic inhibition technique. For quantitative determination, aliquots of the methylene chloride extracts are evaporated to dryness in a rotary evaporator. After the residues are dissolved in ethanol, 0.5N NaOH is added in the hydrolysis step. To remove a number of possible interferences the hydrolyzed phenols are steam-distilled and treated with 1-fluoro-2,4-dinitrobenzene and/or 4-chloro-alpha,alpha,alpha-trifluoro-3,5-dinitrotoluene to form the ether derivatives. Efficiency in the conversion of the phenolic moieties to the phenyl ethers is about 100%. The resulting electron-capturing derivatives enable the carbamate pesticides to be detected in vegetables and fruits at the 0.05 ppm level. Recoveries of 90-94% were obtained from vegetables and fruits fortified with 0.5-2.0 ppm carbaryl, Mesurol, and propoxur.     

Organochlorine pesticide residues in different Indian cereals, pulses, spices, vegetables, fruits, milk, butter, Deshi ghee, and edible oils.

A total of 244 samples of cereals (wheat flour, rice, and maize), pulses (arhar, moong, gram, lentil, and black gram), spices (turmeric, chili, coriander, and black pepper), vegetables (potato, onion, spinach, cabbage, brinjal, and tomato), fruits (mango, guava, apple, and grape), milk, butter, Deshi ghee, and edible oils (vegetable, mustard, groundnut, and sesame) collected from different cities of Northern Province (Utter Pradesh) were analyzed by gas liquid chromatography for the presence of organochlorine pesticide residues. Residues of hexachlorocyclohexane (HCH) and 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) were detected in about 85% of the total samples of cereals, spices, milk, butter, Deshi ghee, and edible oils analyzed in the present study. However, the residue levels were either very small (less than 0.06 ppm) or not detected at all in pulses, vegetables, and fruits as compared with very high concentrations in wheat flour (4.42 and 0.12 ppm), butter (1.19 and 4.85 ppm), mustard oil (1.26 and 2.42 ppm), Deshi ghee (1.10 and 3.84 ppm), vegetable oil (1.02 and 0.59 ppm), groundnut oil (0.51 and 1.49 ppm), and chili (0.48 and 1.92 ppm). The levels of HCH and DDT residues detected in rice, maize, turmeric, corlander, black pepper, and all the vegetables and fruits were also lower than those found in wheat flour, oil, and fat samples analyzed in the present study. These findings suggest that a restricted and controlled use of such persistent pesticides may be useful for decreasing their contamination levels in different food items.     

Nitrogen isotopes as a screening tool to determine the growing regimen of some organic and nonorganic supermarket produce from New Zealand

An isotopic study was performed on nine varieties of organically and conventionally grown vegetables from an organic food market and a chain supermarket in New Zealand. The main aim of the study was to assess the applicability of stable nitrogen isotopes as a screening tool to differentiate between organic and conventional growing conditions of various vegetable types sampled directly off supermarket shelves. This could be further used as the basis of a simple authentication tool to detect noncompliant organic farming practices and false labeling of organic produce. In this study, nitrogen isotopes are found to be an excellent way of identifying faster growing organic vegetables (maturity time to harvest of <80 days), as these vegetables tend to be significantly more enriched in (15)N than conventionally grown vegetables and natural soil N. For slower growing organic produce (maturity time to harvest of >80 days), more information would be required to understand isotopic variations and fractionation effects between vegetables and soil over time as the technique does not discriminate organic from conventional regimens for these vegetables with as much certainty.     

Determination of acequinocyl and hydroxyacequinocyl on fruits and vegetables by HPLC-DAD

A method for determining residues of the new reduced-risk pesticide acequinocyl and its deacetylated derivative hydroxyacequinocyl on fruits and vegetables (grapes, lemons, pears, and tomatoes) by HPLC is described. The pesticides were extracted from the fruits and vegetables with hexane and ethyl acetate solution (1:1, v/v), determined by HPLC-DAD at 250 nm and confirmed by LC/MS. No cleanup was necessary. This method is characterized by recoveries (0.01-4 mg/kg) > 77%, while the coefficient of variation was determined to be less than 11%. The limit of quantitation for both acequinocyl and hydroxyacequinocyl was 0.01 mg/kg for all matrixes.     

Multiresidue method for the analysis of pesticide residues in fruits and vegetables by accelerated solvent extraction and capillary gas chromatography

An analytical procedure using accelerated solvent extraction and capillary gas chromatography with electron capture and flame photometric detections was developed to simultaneously determine residues of different pesticides in fruits and vegetables. Single laboratory validation of the method was carried out for 28 compounds selected from eight pesticide classes, in blank and fortified samples of fresh pear, cantaloupe, white potato, and cabbage. The method had to meet specific established validation criteria for regulatory purposes applicable to our laboratory. At each of the two fortification levels studied, 24 of the 28 pesticides gave recoveries of more than 70% with a coefficient of variation of less than 10%. With respect to existing procedures, the method showed acceptable limits of detection (from 0.0019 to 0.14 microg/g depending on the pesticide and matrix) while minimizing environmental concerns, time, and labor.     

Food and Drug Administration pesticide residue monitoring of foods: 1978-1982

Pesticide residues in foods are reported for the 5-year period 1978-1982 [fiscal years (FY) 78-82]. Results were compiled from the 2 complementary elements that comprise the Food and Drug Administration's (FDA) program for monitoring pesticide residues in foods. Under regulatory monitoring, which focuses on residues in raw agricultural commodities, a total of 49,877 samples (30,361 domestic and 19,516 import) that included fresh fruits and vegetables, grains, milk and dairy products, seafoods, and a variety of processed foods were analyzed. No residues were found in about 55 and 44% of the domestic and import samples, respectively. About 3% of the domestic and 7% of the import samples were classed as violative. Data from the Total Diet Study, which is conducted to determine dietary intakes of a variety of chemicals, showed that residues of 42 pesticides were found in 1044 composites of table-ready foods. Results of FDA's monitoring for FY78-82 demonstrate that pesticide residue levels in the U.S. food supply were generally well below regulatory limits, and dietary intakes were manyfold lower than the Acceptable Daily Intakes established by international agencies.     

Variation of mineral nutrient contents of modern and heirloom cultivars of cabbage in different regimes of soil fertility

An improvement in the mineral nutrient contents of fruits and vegetables is needed to offset reported declines in concentrations of these elements in fruits and vegetables. The declines have been associated with the high productivity of modern cultivars and to depleted soil fertility. This research addressed differences in mineral nutrient concentrations between modern F1 hybrids and heirloom cultivars of cabbage (Brassica oleraceae var. capitata L.)and among fertilization practices with conventional chemical or organic fertilizers and compost. Crop production was greater with the chemical or organic fertilizers than with the compost. Mineral nutrient composition did not vary between modern or heirloom cultivars or among fertilization regimes but varied among cultivars, suggesting that cultivar selection could lead to production of nutrient-rich cabbage. Neither mass of heads nor days to maturation of crops affected nutrient composition.     

基于Web的蔬菜农药残留检测网络监控系统构建(简报)

为保证蔬菜质量安全和消费者健康,该文提出利用.NET技术平台和SQL技术开发成功基于Web的蔬菜农残检测网络监控系统,利用数据库管理系统,通过数据统计和Web报表实现信息的采集和整理;该文给出了系统的结构设计方案、采用的关键技术和主要功能实现方法。该系统在江苏江阴地区实际测试效果良好,可应用于农产品品质检测和安全管理。     

Collaborative study of the determination of endosulfan, endosulfan sulfate, tetrasul, and tetradifon residues in fresh fruits and vegetables.

A method for the determination of endosulfan I, endosulfan II, endosulfan sulfate, tetrasul, and tetradifon residues in fresh fruits and vegetables was studied collaboratively. The method consists of extraction of the product with acetonitrile, ether and elution from a Florisil column with mixtures of hexane, methylene chloride, and acetonitrile, and determination of the residues by electron capture gas-liquid chromatography. This method was studied by 8 collaborators, using apples and cucumbers as the samples. Each sample was spiked with 2 levels of each pesticide. The average per cent recoveries for apples and cucumbers, respectively were as follows: endosulfan I, 103.6 and 101.5; endosulfan II, 102.9 and 100.0; endosulfan sulfate, 100.9 and 92.9; tetrasul, 98.8 and 102.2; and tetradifon, 106.4 and 101.9. The method has been adopted as official first action.     

Levels and incidences of pesticide residues in various foods and animal feeds analyzed by the Luke multiresidue methodology for fiscal years 1982-1986

During a 5 year period from 1982 to 1986, the FDA Los Angeles District Laboratory analyzed 19,851 samples of domestic and imported food and feed commodities for pesticide residues. A single, rapid, multiresidue method was used. The resultant data have been compiled showing the commodities sampled and the identity and range of levels of pesticide residues detected, including an indication of those residue findings that did not comply with U.S. federal tolerance levels. The residue data presented should not be viewed as being representative of the U.S. food supply; rather, the results are indicative of a surveillance- and compliance-oriented sampling of various food shipments collected by the Los Angeles District.     

Immunoreagent generation and competitive assay development for cyprodinil analysis

Cyprodinil is an anilinopyrimidine fungicide applied worldwide for the prevention and treatment of highly destructive plant diseases in a large variety of crops, including cereals, fruits, and vegetables. This paper describes the development of the first reported immunoassays for cyprodinil. Two original haptens have been synthesized and conjugated to different carrier proteins, and polyclonal antibodies have been produced. Moreover, competitive enzyme-linked immunosorbent assays have been developed and characterized for the analysis of this widely used pesticide. The influence of organic solvents and buffer conditions over the assay analytical parameters was studied. The IC(50) values of the optimized immunoassays were 1.6 and 2.8 ng/mL for the direct and indirect formats, respectively. Quantitative recoveries were found using spiked apple and grape juice samples after a simple direct dilution, and a limit of quantification of 20 ng/mL for both fruit matrices was achieved. These immunoreagents could be very valuable for the sensitive, straightforward, and rapid monitoring of cyprodinil residues in foodstuffs.     

A review on phorate persistence, toxicity and remediation by bacterial communities

Pesticides are an integral part in maintaining agriculture and horticultural productivity and play a vital role in meeting the increasing food, fiber, and fuel needs of the growing population. Globally, organophosphate pesticides(OPPs) are among the most common pesticides used due to their high proficiency and relatively low persistence in the environment. However, recent studies have reported problems due to pesticide use, e.g., phorate contamination of aquatic ecosystems(fresh and groundwater), sediments, fruits and vegetables, and forage crops. This review highlights many cases where phorate has been detected above its respective maximum residue limit values. Organophosphate pesticides, including phorate, have negative impacts on both the environment and human health. The ecological and public health concerns of recurrent pesticide utilization have encouraged the research related to environmental fate of pesticides.Bioremediation is an effective, eco-friendly, and financially viable approach for the decontamination and degradation of toxic OPPs from the environment,compared to the costly, unecological, and time-consuming physicochemical approaches, which lead to the generation of byproducts of higher toxicity.Researchers have recognized that a wide range of microbes, mainly bacteria, can degrade this extremely hazardous pesticide. Therefore, this review discusses the present pesticide scenarios, especially phorate contamination, its toxicity, biodegradation, and metabolic products via bacterial communities, both in India and globally. The latest and up-to-date literatures on the use, contamination, and bacterial application of phorate degradation are also summarized. This article offers national and international food safety organizations and public health authorities the ability to be involved in preventing the risks associated with the use of food and nutrition products contaminated with extremely toxic phorate pesticide. This article would also enable researchers to develop comprehensive and sustainable methods to effectively remediate pesticide-contaminated environments. In conclusion, it is envisaged that the successful application of bacterial communities for degradation of phorate would help in understanding the fate and persistence of such toxic pollutants in a better way.     

Effects of agricultural practices on color, carotenoids composition, and minerals contents of sweet peppers, cv. Almuden

Consumers demand organic products because they believe they are more flavorful and respectful to the environment and human health. The effects of conventional, integrated, and organic farming, grown in a controlled greenhouse, on color, minerals, and carotenoids of sweet pepper fruits ( Capsicum annuum), cv. Almuden, were studied. Experimental results proved that organic farming provided peppers with the highest (a) intensities of red and yellow colors, (b) contents of minerals, and (c) total carotenoids. Integrated fruits presented intermediate values of the quality parameters under study, and conventional fruits were those with the lowest values of minerals, carotenoids, and color intensity. As an example, the concentrations of total carotenoids were 3231, 2493, and 1829 mg kg (-1) for organic, integrated, and conventional sweet peppers, respectively. Finally, organic red peppers could be considered as those having the highest antioxidant activity of all studied peppers (agricultural farming and development stage).     

Uptake of quercetin and quercetin 3-glucoside from whole onion and apple peel extracts by Caco-2 cell monolayers

Evidence suggests that regular consumption of fruits and vegetables may reduce the risk of chronic diseases, and phytochemicals from fruits and vegetables may be responsible for this health benefit. However, there is limited knowledge on the bioavailability of specific phytochemicals from whole fruits and vegetables. This study used Caco-2 cells to examine uptake of quercetin aglycon and quercetin 3-glucoside as purified compounds and from whole onion and apple peel extracts. Pure quercetin aglycon was absorbed by the Caco-2 cells in higher concentrations than quercetin 3-glucoside (p < 0.05). Caco-2 cells treated with quercetin 3-glucoside accumulated both quercetin 3-glucoside and quercetin. Caco-2 cells absorbed more onion quercetin aglycon than onion quercetin 3-glucoside (p < 0.05), and the percentage of onion quercetin absorbed was greater than that of pure quercetin, most likely due to enzymatic hydrolysis of quercetin 3-glucoside and other quercetin glucosides found in the onion by the Caco-2 cells. Caco-2 cells absorbed low levels of quercetin 3-glucoside from apple peel extracts, but quercetin aglycon absorption was not detected. Caco-2 cell homogenates demonstrated both lactase and glucosidase activities when incubated with lactose and quercetin 3-glucoside, respectively. This use of the Caco2 cell model appears to be a simple and useful system for studying bioavailability of whole food phytochemicals and may be used to assess differences in bioavailability between foods.