Headspace solid-phase microextraction for the evaluation of pesticide residue contents in cucumber and strawberry after washing treatment

The headspace solid-phase microextraction was developed to examine the organophosphorus (diazinon, malathion, chloropyrifos, quinalphos, profenofos) and organochlorine (chlorothalonil, α-endosulfan and β-endosulfan) pesticide residues in vegetable (cucumber) and fruit (strawberry) samples. The effects of washing by different solutions were evaluated for the reduction of organophosphorus and organochlorine pesticide residues contents. Gas chromatography with electron capture detection was used to analysis the investigated pesticides. The results showed that washing by a non-toxic solution can decrease the concentration of pesticide residues in the fruit and vegetable samples. The data further indicated that acetic acid was the most effective solution in removing the residues of the investigated pesticides from the fruit and vegetable samples when compared to sodium carbonate, sodium chloride and tap water. The amount of pesticides removed by solution washing is related to their water solubility and vapour pressure properties.     

元分析方法评估食品加工对果菜中农药残留的作用

本文采用元分析方法评估食品加工对果类蔬菜中农药残留作用。通过多个数据库文献搜索、数据采集、元分析统计计算,获得特定食品加工方式对果菜中农药残留作用的响应比值、实验间变异及置信区间,并对实验数据进行了同质性Q检验。结果显示研究所取数据具有同质性,自来水清洗、多种溶液清洗、去皮、水煮、清炒、漂烫、烘烤对果菜中农药作用的响应比值均小于0.6,说明食品加工对去除果菜中农药残留有较好作用,可达到40%以上;其中漂烫和烘烤的响应比值分别为0.04和0.01,农药去除效果极佳,可达到95%以上;与自来水清洗相比,乙酸溶液、氯化钠溶液、碳酸钠溶液、碳酸氢钠溶液清洗对农药去除均有较好的效果。元分析获得食品加工对果菜中农药残留作用的响应比值可作为加工因子用于食品安全风险评估中,并可指导果菜安全消费。     

Effects of home preparation on organophosphorus pesticide residues in raw cucumber

The effects of washing with tap water and different detergent solutions, storage at different temperatures and ultrasonic cleaning on organophosphorus pesticide (trichlorfon, dimethoate, dichlorvos, fenitrothion, and chlorpyrifos) residue levels in raw cucumber was investigated. Analysis was carried out by liquid chromatography–tandem mass spectrometry. Washing with detergent solutions proved more effective than tap water. The organophosphorus pesticides reduced from 31.1% to 98.8% after washing with detergent solutions for 20 min. Among detergent solutions, 5% sodium carbonate solution caused the greatest loss in trichlorfon and dimethoate, and 5% sodium bicarbonate solution caused the greatest loss in dichlorvos, fenitrothion and chlorpyrifos. Storage at 4 °C for 48 h caused pesticides reduction by 60.9–90.2%. Ultrasonic cleaning for 20 min lowered pesticides by 49.8–84.4%. The data indicated that home preparation is effective for the reduction of organophosphorus pesticide residues in raw cucumber and it is useful for reducing the dietary exposure.     

Reduction of pesticides residues on okra fruits by different processing treatments

For the first time, the effect of washing, water boiling, chemical boiling, steaming and cooking treatments on the reduction of residues of indoxacarb, fenarimol, acetamiprid and chlorfenapyr in okra fruits was investigated. Residues were analyzed using quick, easy, cheap, effective, rugged, and safe (QuEChERS) method combined with liquid chromatography tandem-mass spectrometry (LC–MS/MS). Our results show that some treatments could significantly decrease pesticide residues. The reduction of residues by washing treatment was not correlated to water solubility: Chlorfenapyr (non-systemic pesticide) was decreased by 90 % and acetamiprid (systemic pesticide) was removed by 48 %. Therefore, we suggest that pesticide residues were washed off by removing the loosely attached pesticides on the okra fruit surface. The time of exposure in both boiling and steaming treatments has no significant effect on reduction of pesticides residues. Additionally, cooking after the washing and boiling treatments reduced the pesticides residues. In particular, acetamiprid was reduced after the cooking treatment to 90 %.     

Biochemical property and gel-forming ability of surimi-like material from goat meat

Biochemical and gel properties of surimi-like material from goat meat (SMGM) as affected by washing solutions including tap water, NaCl, sodium bicarbonate, aluminium sulphate and sodium pyrophosphate, with the same ionic strength of 0.15 for all salt solutions, were investigated. Three-cycle washing (cold solution/water/water; mince:solution ratio of 1:5; 10 min/cycle) was used. Washing solutions differently altered the pH, Ca²⁺-ATPase activity, reactive sulfhydryl, TCA-soluble peptide, total volatile base nitrogen (TVB-N), myoglobin, lipid and thiobarbituric acid reactive substances (TBARS) content of SMGM. Washing can eliminate undesirable lipid, myoglobin, TVB-N and TCA-soluble peptide from goat meat. SMGM washed with water and NaCl can form stable gels whereas SMGM washed with bicarbonate, pyrophosphate and aluminium sulphate formed very mushy gel/aggregate with high released water. SMGM gels particularly that washed with NaCl had higher breaking force, deformation and whiteness with lower TBARS content, species odour and expressible drip than unwashed mince. Therefore, SMGM can be optimally produced by washing with NaCl solution.     

Selected Washing Processes Affect Thermal Gelation Properties and Microstructure of Mechanically Deboned Chicken Meat

Cooked mechanically deboned chicken meat (MDCM), washed with tap water, 0.5% sodium bicarbonate, sodium phosphate buffer (pH 7.2; ionic strength, 0.1), or 0.1M sodium chloride had increased (P lt;0.05) gel strength compared to unwashed MDCM. The selected washing solutions affected (P lt;0.05) lightness (HunterLab L values) of washed meat, and also had a slight (Plt;0.05) influence on water-holding capacity and textural properties. These differences were attributed to pH and washing solvent residue in the washed MDCM. Scanning electron microscopy revealed distinct differences between the washed and unwashed MDCM. The washed meat showed a fibrous protein network structure resulting from protein gelation.     

Behavior of pesticides in tomatoes during commercial and home preparation

Monitoring of pesticide residues in Egyptian tomatoes and its products was studied. The average contents of HCB, lindane, dieldrin, heptachlor epoxide and DDT derivatives were detected at levels 0.009, 0.003, 0.006, 0.008 and 0.083 mg/kg, respectively. On the other hand, the levels of dimethoate, profenofos and pirimiphos-methyl were 0.461, 0.206 and 0.114 mg/kg, respectively. In ketchup and paste samples, most organochlorine and organophosphorus pesticide residues were not detectable. The distribution patterns of pesticide residues within the cuticular and subcuticular tissues in tomatoes were also studied. The skin samples were found to contain the highest levels of HCB, lindane, dieldrin and DDT derivatives. The investigation also indicated that washing with water and/or detergent solution were necessary to decrease the intake of pesticide residues. Freezing, as well as juicing and peeling, were necessary to remove pesticide residues in the skin. Cooking of tomatoes (including processing tomato to paste) helped to eliminate most pesticide residues from contaminated tomatoes. ©     

Effects of aqueous washings on colour and nutrient quality of mechanically deboned chicken meat

Mechanically deboned chicken meat (MDCM) was washed with water, 0·5% NaCl or 0·5% NaHCO(3) solutions. Approximately 75·5% of the total hemoprotein pigments were removed by washing of MDCM with a sodium bicarbonate solution which resulted in the best colour improvements in the samples. Approximately 18·7% of total lipids were removed as a result of aqueous washing. The yield of proteins ranged from 56·5% after one washing with water to 43·4% after washing with water and then with a sodium bicarbonate solution. The Hunter L and a colour parameters of the samples correlated well with the total hemoproteins (correlation coefficients -0·984 and +0·947, respectively); corresponding correlation coefficient with the Hunter b value was only +0·693.     

剁辣椒家常加工对5种农药残留的影响

为研究剁辣椒家常加工过程对农药残留的影响,在实验室模拟沉积农药条件下,通过优化分散固相萃取方法建立了剁辣椒中5种农药的QuEChERS结合液相色谱-串联质谱检测方法,研究了经水洗、晾干、切碎、加盐腌制4道家常加工工序后,吡虫啉、啶虫脒、精甲霜灵、嘧菌酯和苯醚甲环唑5种农药在剁辣椒加工过程中的残留量变化情况。结果表明:剁辣椒中5种农药的残留量随着加工工序的增加而呈下降的趋势,全过程加工因子分别为0.2、0.32、0.23、0.21和0.14。经过剁辣椒家常腌制21 d后5种农药的农药残留的膳食暴露量大大降低,膳食风险指数分别较未加工降低了80.6%、68.7%、76.3%、78.4%、85.9%。而在不同加工工序中不同农药的加工因子变化有差异,这与农药本身的理化特性密不可分,log Kow（辛醇水分配系数）值小的农药（吡虫啉和啶虫脒）,在水洗处理下的残留量少,且冲洗处理较浸泡处理去除农药效果好;而log Kow值大的农药（嘧菌酯和苯醚甲环唑）,在加盐腌制处理下的残留量少,且在剁辣椒腌制的无氧环境中农药降解速率逐渐变缓。因此剁辣椒家常加工过程可以减少农药残留量,提高剁辣椒食用安全性。     

不同洁净度葡萄的葡萄酒发酵效果研究

使用武宣地区3种红曲米作为发酵剂酿造红曲柿酒，分析其理化指标和挥发性风味成分差异，并采用Illumina MiSeq高通量测序技术检测3种红曲米的细菌多样性，以解析不同细菌群落在红曲柿酒发酵过程中的作用。结果表明，不同红曲柿酒总酸和挥发酸含量差异显著（P＜0.05）；挥发性酸类物质组成存在较大差异，其中红曲米样品WX-2制成的红曲柿酒挥发性酸类物质含量最高（10.0%）。从3种红曲米样品共检测出19个细菌门，239个细菌属，共有优势菌门为变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、拟杆菌门（Bacteroidetes）、放线菌门（Actinobacteria）；共有优势菌属为伯克霍尔德菌属（Burkholderia）、克雷伯氏菌属（Klebsiella），WX-2样品中优势菌属还有醋菌属（Acetobacter）、小球菌属（Pediococcus）、乳酸杆菌属（Lactobacillus），均为产酸菌株。表明红曲米细菌群落结构与红曲柿酒酸类物质的形成紧密相关。     

鲜切生菜加工过程对5种农药残留的影响

本文旨在研究鲜切生菜制备过程中不同处理过程对五种农药残留的影响,并评估农药残留对人体的健康风险。通过开展田间试验研究三种杀虫剂(吡虫啉、虫酰肼、氯氰菊酯)和两种杀菌剂(戊唑醇、嘧菌酯)在模拟商用鲜切生菜处理条件下的耗散情况,采用基于乙腈的乙二胺-N-丙基硅烷(Primary secondary amine,PSA)填料分散固相萃取净化,气相色谱-串联质谱和液相色谱-串联质谱分析验证5种农药残留分析方法的可靠性并对农药残留进行检测。结果表明,5种农药残留在用次氯酸钠洗涤后均出现显著性下降(P<0.05),在切、清洗、离心脱水、冷藏保存时鲜切生菜中5种农药的加工因子均低于1,整个处理过程大大降低了农药残留水平。体外模拟胃肠环境下5种农药的生物可给性均未达到50%。不同添加水平下,生物可给性依次为:氯氰菊酯 > 嘧菌酯 > 戊唑醇 > 吡虫啉 > 虫酰肼,结合供试农药的每日容许摄入量(Allowable Daily Intake,ADI)值发现,对人体的健康风险而言,3种杀虫剂中虫酰肼最安全,吡虫啉比氯氰菊酯安全,而杀菌剂嘧菌酯比戊唑醇更安全。通过加工可去除生菜中的农药残留,降低膳食暴露量,对保障消费者的膳食安全具有积极意义。     

Chicken Skin Composition As Affected By Aqueous Washing

Broiler skin was washed in either 0.1M sodium chloride (pH 7.0) or 0.5% sodium bicarbonate buffer (pH 8.4) to reduce water-soluble proteins and fat. Washing increased moisture and total protein content (P<0.05) of skin. Ash content was lower (P<0.05) in skin washed in 0.5% sodium bicarbonate buffer compared to unwashed and 0.1M sodium chloride washed skin. Fat content decreased (P<0.05) following washing. Salt extractable proteins and collagen content remaining in skin increased following washing (P<0.05). Water-soluble proteins remaining in washed skin were lower (P<0.05). SDS-PAGE gel patterns for salt extractable proteins remaining in skin after washing revealed more intense bands in regions of myosin (200K daltons), M-proteins (165K daltons) and C-protein (135–140K daltons) and 31-45K daltons.     

Household vegetable processing practices influencing occurrence of pesticide residues in ready-to-eat vegetables

Influence of vegetable processing on pesticide residues in ready-to-eat vegetables studied at the experimental level does not necessarily reflect actual situation at household level. This study assessed influence of household vegetable processing practices on pesticide residues in ready-to-eat vegetables at household level in Arusha, Tanzania. Data on vegetable handling practices were collected through observations and physical interviews in 70 households. Samples of raw and ready-to-eat vegetables were collected from the households for pesticide residues analysis. Detectable pesticide levels were found in 46% of raw and 14% of ready-to-eat vegetable samples. Pesticide residues detected were in the groups of organophosphates (22.8%), pyrethroids (14.3%), organochlorines (7.14%), benzoic acids (7.14%), and carbamates (5.71%). Unauthorized pesticides (dichlorvos, tetramethrin, and bendiocarb) and environmentally persistent pesticide (dieldrin) were found at levels above their respective maximum residue levels. Washing of vegetables twice or more (p = .01) or peeling (p = .008) was significantly associated with reduction of pesticide residues. There was a significant association between occurrence of pesticide residues in ready-to-eat vegetables and washing of minor ingredients with the water used to wash major ingredients (p = .001). Household practices of washing of vegetables with portable water followed with peeling can reduce pesticide residue levels significantly.     

Pesticide residues in washing water of olive oil mills: effect on olive washing efficiency and decontamination proposal

BACKGROUND: Washing olives in the olive oil mill (a commonly used preliminary step to remove foreign materials and leaves) can help to remove pesticide residues, especially herbicides that are present in olives due to contamination either during application or as a consequence of contact with contaminated soil. The aim of the present work was the study of washing efficacy during washing cycles, i.e., from the beginning of the cycle until the water was changed. RESULTS: Four active ingredients, namely diuron, oxyfluorfen, terbuthylazine and endosulfan (α and β isomers) as well as the latter's degradation product endosulfan sulfate, were the most frequently found pesticides in raw olives after harvest. At the beginning of the washing cycle, diuron, terbuthylazine and oxyfluorfen residues were effectively removed from olives. However, progressive water contamination with pesticide residues decreased the efficiency of the washing step, specially for diuron and terbuthylazine residues. CONCLUSION: A decontamination method to enable water recycling in olive oil mills was proposed and optimized. It employed FeCl₃ as coagulant and active charcoal as adsorbent, and was effective in removing both suspended solids and pesticide residues. Copyright © 2008 Society of Chemical Industry     

Similar Reduction of Salmonella enterica Typhimurium on Grape Tomatoes and Its Cross-Contamination in Wash Water by Washing with Natural Antimicrobials as Compared with Chlorine Treatment

Thymol (THY), a generally recognized as safe (GRAS) compound found in thyme oil, has inhibitory effects against foodborne pathogens including Salmonella. Hydrogen peroxide (H₂O₂) is another GRAS agent to effectively inactivate Salmonella. The aim of the current study was to develop a GRAS wash solution containing THY (or H₂O₂) and other GRAS antimicrobials (organic acids and food surfactants) that would effectively reduce Salmonella enterica on grape tomatoes and minimize cross-contamination in washing water. A systematic approach including minimum inhibitory concentration and minimum bactericidal concentration tests, inhibition zone tests, and small-scale and scaled-up tomato washing tests was used to develop such wash solutions. Grape tomatoes surface-inoculated with S. enterica Typhimurium were washed with selected solutions containing combination of 0.2 mg/ml THY, 5 % sodium dodecyl sulfate (SDS) and 2 mg/ml acetic acid (AA), 800 ppm H₂O₂, combination of 200 ppm H₂O₂ with 4 % SDS, or 200 ppm chlorine for 2 min. THY 0.2 mg/ml + SDS 5 % + AA 2 mg/ml, 800 ppm H₂O₂, or 200 ppm chlorine achieved around 7.5 log reductions of Salmonella on the tomatoes as compared to the control in tests involving 10 or 100 g tomatoes. More than 5.0 log reductions in the spent washing solutions (0.2 mg/ml THY + SDS 5 %?+?2 mg/ml AA; 800 ppm H₂O₂) was observed. None of these antimicrobial washes changed the color, pH, texture, sensory quality of the tomatoes during 16-day storage at 4 and 22 °C. These treatments also achieved a 1.3 log reduction of total aerobic bacteria. Thus, washing with 0.2 mg/ml THY + SDS 5 %?+?2 mg/ml AA and 800 ppm H₂O₂ as alternative to chlorine-based washing could be an effective method to inactivate Salmonella on tomatoes and reduce the transmission of pathogens from tomatoes to washing solutions.     

冷藏与家庭处理对黄瓜中7 种农药残留的影响

通过对黄瓜中7 种农药及2 种代谢物的残留量来评价冷藏与清洗、烹饪处理对农药及其代谢产物的影响。结果表明,在5 ℃贮藏条件下,黄瓜中的农药残留量随着冷藏时间的延长越来越低,10 d后黄瓜中的7 种农药降解率达38.9%～58.3%;清水清洗后7 种农药降解率在27.17%～80.00%之间,而清洁剂清洗的降解率可达33.33%～90.00%,2 种清洗方式所产生的农药降解率的差异与农药的水中溶解度相关;蒸、煮、炒3 种处理均能有效降低黄瓜中的农药残留量,煮处理对黄瓜中的农药消除效果最好,降解率在22.76%～85.00%之间,炒处理次之,降解率在21.52%～75.00%之间,蒸处理最差,在10.13%～53.25%之间。在烹饪处理过程中,烹饪所产生的温度为农药降解的关键因素。     

不同清洗方法对草莓中农药残留清洗效果的研究

目的考察不同清洗方法对草莓中农药残留的清洗效果,确定减少草莓中农药残留的最优清洗方法。方法采用正交设计的方法,用最少的实验次数,考察清洗溶剂、清洗方式、清洗时间、清洗温度等因素对清洗效果的影响,每个因素下设有不同的影响水平,充分考虑各个因素下不同水平对清洗结果的影响,共设计27组不同的清洗方法。采用高效液相色谱-串联质谱法同时测定8种农药的残留量,比较清洗前后的农药残留量作为清洗效果的评价指标。结果以2%碳酸氢钠水溶液为清洗溶剂,在40℃的条件下超声10 min取得的清洗效果最好,能将5种不同的农药残留量降低30%以上。结论该方法设计科学,结果可靠,容易操作,可用于草莓日常清洗的方法,为草莓的食用安全提供了一定的保障。     

How effective are common household preparations on removing pesticide residues from fruit and vegetables? A review

Nowadays, the use of pesticides is inevitable for pest control in crops, especially for fruit and vegetables. After the harvest from raw agricultural commodities, the amount of pesticide residues in food is mainly influenced by the storage, handling and processing that follow. If good agricultural and good manufacturing practices are enforced effectively, the amount of pesticide residues would be brought below the corresponding maximum residue level. Thus, the consumption of raw and/or prepared fruit and vegetables would be safe. Nonetheless, reports regarding pesticide residues in fruit or vegetables on mass media have been worrying consumers, who are concerned about the adverse effects of pesticide residues. As a result, consumers perform household processing before consumption to reduce any related risks. However, can these preparations effectively remove pesticide residues? Reviewing the extensive literature, it showed that, in most cases, washing and soaking can only lead to a certain degree of reduction in residue level, while other processing such as peeling, soaking in chemical baths and blanching can reduce pesticide residues more effectively. In general, the behaviour of residues during processing can be rationalised in terms of the physico‐chemical properties of the pesticide and the nature of the process. In contrast, the reported studies are diversified and some areas still lack sufficient studies to draw any remarks. Recommendations are provided with respect to the available information that aims to formulate an environmental friendly, cost‐effective and efficient household processing of fruit and vegetables to reduce pesticide residues. © 2017 Society of Chemical Industry     

Effect of washing treatments on pesticide residues and antioxidant compounds in Yuja (Citrus junos Sieb ex Tanaka)

This study investigated the removal efficiency of pesticide residues and microorganisms, and changes of the amount of antioxidant compounds on yuja (Citrus junos Sieb ex Tanaka) by various washing methods. The washing methods were mechanical washing (MW), mechanical washing after soaking in SAcEW, strong acidic electrolyzed water (SAcEW+MW), and soaking detergent solution (DW), with a tap water washing (TW) as the control. After treatment of MW and SAcEW+MW, the microbial count were 3.71 and 2.66 log CFU/g, respectively. Compared with the TW treatment (5.77 log CFU /g), MW and SAcEW+MW treatments showed a higher reduction. As a result of pesticide residue, the SAcEW+MW removed 70.5–98.1% and was the most effective, regardless of the pesticides. Antioxdant activities, as measured by DPPH radical, ranged from 20.36 to 21.27% and there was no significant difference from the washing methods. The results of this study demonstrated that the SAcEW+MW was the most effective method for removing residual pesticides without affecting the quality of the yuja.     

Distribution behaviour of acaricide cyflumetofen in tomato during home canning

The distribution behaviour of cyflumetofen in tomatoes during home canning was studied. The targeted compound cyflumetofen was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each process step, which included washing, peeling, homogenisation, simmering and sterilisation. Results indicated that more cyflumetofen was removed by washing with detergent solution compared with tap water, 2% NaCl solution and 2% CH₃COOH solution. Peeling resulted in 90.2% loss of cyflumetofen and was the most effective step at removing pesticide residues from tomatoes. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PF of the peeling process for cyflumetofen was 0.28.