Endocrine disrupting activity in fruits and vegetables evaluated with the E-screen assay in relation to pesticide residues

Food is likely to be one of the most important routes of human exposure to endocrine disrupting compounds (EDCs). In the present study, we evaluated the total estrogenic activity of fruits and vegetables, which was calculated using the human breast cancer cell line (MCF-7 BUS) proliferation assay (E-screen), in relation to pesticide residues. We analysed 44 food samples, 30 fruits and 14 vegetables. Of these samples, 10 did not contain any pesticide residues. The other 34 samples contained from 1 to 7 pesticide residues in concentrations ranging from 0.03 to 1.91 ppm. Estrogenic activity was detected in the 59% of samples tested. The positive controls used were 17-β-estradiol (E2), the phytoestrogen genistein and the pesticide endosulfan. The average value of estradiol equivalency quantity (EEQ) for all positive samples was 0.15±0.32 μg/100g. A low correlation was found between the concentration of pesticide residues and the EEQ values (Spearman correlation r=0.376 and p=0.012). Using values obtained from the literature, we compared the estrogenic activity of food samples with the intrinsic content of phytoestrogens, but we found no correlations. Our results also suggested that the calculated intake of dietary EDCs might represent a concentration comparable to the normal endogenous estrogen concentration in human blood.     

福州市蔬菜农药残留检测与分析

采用农业行业标准NY/T761-2008检测方法,用气相色谱仪对福州市3家超市和3家农贸市场销售的16个蔬菜品种共60份样品进行有机氯及拟除虫菊酯类农药残留的检测,并根据GB2763 - 2005标准判定检出超标情况.结果表明:农药残留检出率为31.67％;农药残留超标率为3.33％.从蔬菜种类上,白菜类、瓜类的检出率...     

蔬菜中有机磷农药残留的高效液相色谱分析

应用高效液相色谱法测定蔬菜中有机磷农药残留量。采用高效液相色谱法,C18色谱柱、流动相为甲醇：水(V：V)=70：30,用紫外检测器检测。测定了蔬菜中甲1605和久效磷两种常用有机磷农药的残留量。该法相关性好,线性范围广,精密度高,准确度好。     

基于酶生物传感器法检测果蔬中毒死蜱残留的提取工艺研究

使用自主研制的酶生物传感器型农残检测仪进行农药残留检测,通过筛选可测果蔬种类、调整优化样品处理大小、样品加标后静置时间、样品与提取液比例和振荡提取速度,提高检测用酶对农药的抑制敏感性,从而达到降低农药检出限、提高回收率的目的。主要设置的参数如下:样品处理方式分为打碎、切碎(切成1 cm×1 cm和1. 5 cm×3 cm大小);加标后静置时间为5 min、15min、30 min、60 min和90 min;料液比为1∶1、1∶2. 5、1∶5、1∶7. 5和1∶10;振荡提取速度为0 r/min、110 r/min、190 r/min和225 r/min;主要测定的农药为毒死蜱。结果发现,不同果蔬品种对固定化酶的抑制率影响小,样品大小为1 cm×1 cm、加标后静置时间为5 min、料液比为1∶1、加入提取剂后的振荡速度为190 r/min为最佳前处理方式组合。酶生物传感器农残检测仪能够满足快速检测果蔬中有机磷农药残留的需要。     

Occurrence and risk assessment of organophosphorus pesticide residues in Chinese tea

Tea is the second widely consumed beverage next to water. Tea drinking is one of the important pathways for human exposure of organonphosphorus pesticide. Consequently, incidence of organonphosphorus pesticide residues and risk assessment should be clear. In this study, the level of organonphosphorus pesticide residues in 810 Chinese teas manufactured between 2010–2013 was investigated using gas chromatography coupled with tandem mass spectrometry and a flame photometric detector. Incidence of organonphosphorus pesticide residues occurred with a frequency of 29% and the average concentration of 93 μg kg^?1. The residue levels varied from tea types, sale spots, and production area. Chlorpyrifos, isocarbophos, and triazophos were the only three organonphosphorus pesticides with detectable residues, and the detectable rates were 13.0%, 13.6%, and 17.4%, respectively. The corresponding average daily intake of chlorpyrifos, isocarbophos, and triazophos by tea drinking was 0.000083 μg kg^?1 bw day^?1, 0.0036 μg kg^?1 bw day^?1, and 0.0022 μg kg^?1 bw day^?1. These results showed that the total hazard quotient of organonphosphorus pesticide pesticides from tea drinking was less than 0.02 and that the tea-drinking originated organonphosphorus pesticide exposure had a little adverse health effect for human being.     

Health risk assessment from dermal exposure to pesticide residues on vegetables among greengrocers in fresh market,Bangkok, Thailand

Pesticide residues (PRs) in market vegetables have been reported regularly. Greengrocers may be exposed to several sorts of PRs on vegetables through hand contact. Health risk assessment from occupational exposure to PRs on vegetables is particularly concerning. This study was conducted among 91 vegetable vendors at a large fresh market in Bangkok. Hand wipe samples were collected in the dry season to extract and analyze PRs including organophosphates (OPs), pyrethroids (PYs), and carbamates (CAs) by gas chromatography (GC-FPD/GC-μECD) and liquid chromatography (LC–MS). The results showed that all wipe samples contained OPs, PYs, and CAs, mainly chlorpyrifos (0.01–0.14 µg/hands) and cypermethrin (0.42–11.64 µg/hands). The frequently detected PRs were aldicarb (87.2%), carbofuran (69.2%), permethrin (63.7%), and profenofos (60.0%). At 99th percentile values of PR exposure, average daily dose was 2.42 × 10^?5 mg/kg/d and hazard index did not exceed the acceptable level (0.287). Glove wearing, hand washing, and work-related factors were significantly associated with PRs on hands after adjusted for gender (p-value < 0.05). Greengrocers may therefore not be at risk from PRs on vegetables and exposure via hands during their work. However, these findings suggest that proper personal hygiene practices among greengrocers should be considered to prevent them from PR exposure and potential health risks.     

Biomechanics of fruits and vegetables

The scope of fruit and vegetable biomechanics is reviewed. Sources of mechanical injury to produce in harvesting, processing, storage, packaging and transportation are briefly described. A survey of produce handling and transportation environments was conducted, whereby an envelope model encompassing composite spectra of trucks, railroad, marine and cargo aircraft is presented. The protective quality, i.e. strength of shipping containers is quantified in static and dynamic loading such as encountered in storage, handling and transportation. Mechanical response of fruits and vegetables in quasistatic and dynamic loading are formulated by a nonlinear rheological model, whereby a time and deformation dependent relaxation modulus is defined. A realistic link is established between the model and real fruits and vegetables by test procedures for determination of the parameters in the governing nonlinear equations. Based on the nonlinear relaxation modulus, mechanical damage of fruits and vegetables is quantified for static compression, transients and vibration loading as well as for combined static and dynamic loading, by equations of contact circle diameter, bruise depth and contact pressure. Distribution of loads over a maximal number of contact points per fruit is linked to geometrical patterns of produce packs. The application of Shock Damage Boundary techniques for produce-package testing is described along with a case study comparing the protective qualities of two types of apple packs. Produce damage quantification by direct fruit inspection in terms of a 'Bruise Index' is described, including a practical example, comparing the protective qualities of three types of apple packs in shipping tests. Indirect methods of mechanical injury evaluation, based on weight loss and CO2 emission differences between bruised and wholesome fruits are also briefly discussed.     

Levels of pesticide residues in breast milk and the associated risk assessment

The aim of this study was to determine the types and levels of organochlorine pesticides (OCPs) present in the human milk collected from cities in eastern and central Saudi Arabia. This study is part of assessment of various persistent organic pollutants (POPs) in human milk in four cities of eastern and central Saudi Arabia, namely, Riyadh, Al-Kharj, Al-Jobail and Al-Dammam. Milk samples were collected from 50 donors according to the WHO/UNEP protocol for monitoring human milk for POPs. The OCPs in each of the 50 milk samples were analyzed using as triple quadrupole gas chromatography mass spectrometry-mass spectrometry detection (GC–MS/MS). Quality assurance included the analysis of blank, spiked and reference samples. Sixteen different OCPs were identified namely: aldrin, dieldrin, endrin, hexachlorobenzene, alpha, beta, gamma and delta hexachlorocycohexame, pp’-,op’-DDT, pp’-DDE, pp’-DDD, alpha and gamma chlordane, heptachlor, mirex and methoxychlor. The results of the analysis OCPs in human milk samples indicated that the tested positive samples for one or more pesticide at the limits of determination used in this study. As required by the Stockholm Convention on POPs, the levels of certain POPs in human milk will serve as an indicator of the effectiveness of the treaty in eliminating or reducing emissions of selected POPs. This study contributes to that effort by providing seline data on current levels of OPCs in human milk in Saudi Arabia.     

Risk assessment of population exposure to toxic trace elements via consumption of vegetables and fruits grown in some mining areas of Armenia

Consumption of unsafe food is one of the most important public health concerns. Trace elements’ contamination caused by direct or indirect activities of mining industries is of importance in this respect. The present study was conducted to assess the chronic dietary exposure and related health risks of trace elements through the intake of selected vegetables and fruits grown under the impact of mining industry in Syunik region (Armenia). Consumption data were obtained via food frequency questionnaire and the concentrations of Cu, Mo, Ni, Cr, Pb, Zn, Hg, and Cd in different fruits and vegetables were determined. Moreover, by combining concentration data with consumption data, estimated daily intake, and target hazard quotient were assessed for each element. The results obtained showed that mean concentrations for Pb and Hg in some vegetables exceeded maximum acceptable levels set by international organizations. Hazard indexes > 1 have been obtained in some cases indicating that for some vegetables (particularly for potato, carrot, maize, onion leaf, grape, bean, beet, sweet pepper, eggplant, and tomato) habitual consumption has a potential to pose adverse health effect to the local population.     

金华北山区部分绿色蔬菜的营养成分和有害物质测定

对马铃薯、菜豆、萝卜和番茄等４种绿色蔬菜进行营养成分和有害物质的全面测定。结果表明：绿色蔬菜具有高营养、无毒的特点。（１）４种绿色蔬菜的含钙量分别为一般蔬菜同一品种的２４０％、１９８．５％、１６３．７％和１５７．８％,含铁量分别为１７．４倍、８．７倍、１０．７倍和１２．７倍,含磷量分别为１１８．２％、１０２％、１６３．６％和１７７．８％,并具有较高的镁、锌、铜和锰等元素的含量。（２）４种绿色蔬菜的镉、砷、汞、氟、六六六、ＤＤＴ、敌敌畏、乐果、马拉硫磷、对硫磷、甲胺磷、杀螟硫和倍硫磷等１３项有害物质全部符合绿色食品标准。（３）４种绿色蔬菜的ＶＢ１含量分别增加２０％、２２．２％、１６．７％和６％,ＶＢ２分别增加３０％、１２％、１３５％和２６．７,Ｖc分别增加８．６％、６８．９％、１２．１％和１８．１％,胡萝卜素分别为一般同种蔬菜的１６倍、２．９倍、１３．５倍和４．５倍。（４）其蛋白质含量也分别增加１８．５％、１３．９％、７．５％和３０％,灰分分别为２．０８倍、３．１５倍、２．８５倍和２．９６倍,总糖分别为一般同种蔬菜的９１％、１０１．１％、１９１．３％和９５．２％,粗纤维分别为１１３．３％、８９．２％、８６．７％和１０５％。     

Toxicological evaluation of multi-class pesticide residues in vegetables and associated human health risk study for adults and children

This article describes, for the first time in 10 years, the toxicological evaluation of pesticide residues in highly consumed vegetables (35 commodities) and health risk studies. Among 1075 vegetable samples consisting mainly of tuber, root, fruiting, and Brassica, 20% of samples contained 38 pesticides in the range of 0.005–18.7 mg/kg and 1% > maximum residue limits (MRLs). Organophosphates and chloronitrile were most frequently found (20%) in the pesticide class. The highest concentration of 18.7 mg/kg was noted for dichlofluanid. Fruiting vegetables (8%), especially tomatoes (5%), were the most contaminated, while multi-residues were determined in 5% of the samples. Risk assessment was performed by analytical results and consumption on the 97.5 percentile expressed as hazard index (HI) and hazard quotient (HQ). The highest chronic HI was calculated for diazinon in lettuce (32% Acceptable Daily Intake (ADI) adults and 36% children) and for forbidden dieldrin in carrots (26%, 62% ADI). The highest acute HI was estimated for dichlofluanid in lettuce (69% Acute Reference Dose (ARfD)) for adults, whereas for children it was above the acceptance values of ARfD (168%). Organophosphate insecticides with common mode of action showed the greatest HQ (108% ADI). Vegetables may not be a serious problem for consumers, but investigations on pesticide residues are necessary to ensure food safety and the protection of human health, especially toward children who are more highly exposed to pesticides than adults.     

Occurrence of natural Bacillus thuringiensis contaminants and residues of Bacillus thuringiensis-based insecticides on fresh fruits and vegetables

A total of 128 Bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in Denmark were characterized. Of these strains, 39% (50/128) were classified as Bacillus thuringiensis on the basis of their content of cry genes determined by PCR or crystal proteins visualized by microscopy. Random amplified polymorphic DNA analysis and plasmid profiling indicated that 23 of the 50 B. thuringiensis strains were of the same subtype as B. thuringiensis strains used as commercial bioinsecticides. Fourteen isolates were indistinguishable from B. thuringiensis subsp. kurstaki HD1 present in the products Dipel, Biobit, and Foray, and nine isolates grouped with B. thuringiensis subsp. aizawai present in Turex. The commercial strains were primarily isolated from samples of tomatoes, cucumbers, and peppers. A multiplex PCR method was developed to simultaneously detect all three genes in the enterotoxin hemolysin BL (HBL) and the nonhemolytic enterotoxin (NHE), respectively. This revealed that the frequency of these enterotoxin genes was higher among the strains indistinguishable from the commercial strains than among the other B. thuringiensis and B. cereus-like strains isolated from fruits and vegetables. The same was seen for a third enterotoxin, CytK. In conclusion, the present study strongly indicates that residues of B. thuringiensis-based insecticides can be found on fresh fruits and vegetables and that these are potentially enterotoxigenic.     

Antioxidative activity of selected fruits and vegetables

Recent studies have demonstrated that dietary plants are rich source of antioxidants and can contribute to the protection from age-related diseases. The aim of our study was to determine the total antioxidant capacity of extracts from different kinds of fruits and vegetables, and to examine their inhibitory effect on the oxidative damage to proteins in vitro. For determination of antioxidant capacity we used two direct methods. Among the food materials chosen for the present study, blueberries and red beets gave the maximum antioxidant activity. The lowest activity was determined in pears and green beans. Some extracts were more active in one method, while their activity was lower using the other method. To investigate inhibitory effects of fruits and vegetables extracts on the oxidative damage to proteins in vitro, we induced the oxidative damage to plasma proteins by sodium hypochlorite leading to formation of carbonyl compounds detected by spectrophotometric method. All extracts of fruits and vegetables showed inhibitory activity on the oxidative damage to proteins with raspberries and leek as most effective. Results of this study will be useful as an aid for dietary choices to increase antioxidant intake and will allow the investigation of the relation between dietary antioxidants and oxidative stress-induced diseases.     

Market diseases of fresh fruits and vegetables

Bruising, crushing, and other mechanical injuries cause very serious losses during the handling, transportation, storage, and marketing of fresh fruits and vegetables. Spoilage caused by molds and bacteria exacts a heavy toll. Freezing, chilling injury, and various physiological disorders add to the consumer cost of living. Careful handling, proper refrigeration, good marketing practices, and the use of safe, approved chemical treatments can reduce marketing losses.     

Gamma radiation effects on fruits and vegetables

Several million dollars are lost in the United States each year as a result of post harvest diseases of crops. Claim costs to railroads alone in 1958 amounted to $11 million. This work demonstrates that it is possible to extend the shelf-life of fresh fruits and vegetables at room as well as at refrigeration temperatures by gamma radiation, by surface pasteurization, sprout inhibition, and also by retarding the ripening processes. The information presented should be useful to researchers, shippers, packers, and processors.     

Evaluation of selected plant growth regulators and fungicide residues in fruits for dietary risk assessment

A total of 96 samples of fresh fruits were collected to investigate the residues of selected plant growth regulators and fungicides. The analyses utilized ultra-high-performance liquid chromatography coupled with tandem mass spectrometry after a modified QuEChERS method. The results were evaluated according to maximum residue limits (MRLs) by the Chinese regulation. All blueberries, litchis, and watermelons were pesticide-free, and only one (1%) fruit sample contained pesticide residues above MRLs. Concerning the most frequently detected pesticide residues, carbendazim was found in 20% of the samples analyzed. Data obtained were then used to estimate the potential health risks associated with the exposures to these pesticides. The short-term risks were below 3.25% and the long-term risks were also very low, ranging from 0.0005% for dimethomorph to 0.4302% for prochloraz.     

Storage characteristics of some vegetables and soft fruits

Rates of carbon dioxide production, in air and in 3 % 0₂, over a range of temperatures, were measured for over thirty commodities, and rates of evaporation, under known water vapour pressure deficit, measured for most of them. Optimum storage conditions in air for each commodity were determined. Storage life under these optimum conditions, and under the nearest practical approximation to them, was estimated. In most cases the optimum temperature is o^oC, examples of exceptions being runner beans, cucumbers, potatoes, green peppers and tomatoes. The humidity should usually be high, 100 % r.h. often being optimal, particularly for leafy vegetables, provided the temperature is low. Commodities resistant to evaporation, however, such as the onion, may with advantage be stored at lower humidities, thus reducing the microbial hazards.