Quality of Fungicide Treated and Individually Shrink-Wrapped Tomatoes

Fungicide-treated mature green and pink tomatoes were individually shrink-wrapped with plastic films and stored at 13°C and 18°C. Shrink-wrapped pink tomatoes lost less water than unwrapped tomatoes, but there were no significant shelf-life or quality differences. The shelf-life of mature green tomatoes at 18°C, however, was increased 10 days by shrink-wrapping. Color development of wrapped mature green tomatoes at 18°C was delayed. Wrapped fruit at both temperatures were firmer than the controls. Titratable acidities and soluble solids of wrapped fruit were lower than those of the unwrapped fruit at 13°C, while no significant changes were observed in citric acid or monosaccharide concentrations. The differences in titratable acidities and soluble solids in the wrapped and unwrapped fruit stored at 18°C were not significant.     

Research Watch: Fungicide leaching

Groundwater.     

Research Watch: Fungicide analysis

Methods.     

Fungicide effects on ammonium and amino acids of Monastrell grapes

The influence of six fungicides (famoxadone, fenhexamid, fluquinconazole, kresoxim-methyl, quinoxyfen and trifloxystrobin) on the amino acids and ammonium composition of grapes (var. Monastrell) are studied. The treatments were performed under critical agricultural practices (CAP), 6 h before grape collection. The analytical determination of amino acids and ammonium were made using HPLC with a photodiode array detector (DAD), after derivatisation of the sample with diethyl (ethoxymethylene)malonate (DEEMM). The application of fungicides to the vine decreased concentrations of nitrogenous compounds in grapes. Furthermore, the qualitative and quantitative effects on the amino acids in the grapes depended on the type of fungicide used. The fungicides which affected the highest number of amino acids were famoxadone and fenhexamid, while quinoxyfen affected the lowest number of amino acids. Grapes treated with famoxadone contained the lowest concentration of total amino acids.     

四川烤烟赤星病的生物学特性及药剂筛选

为明确四川烤烟赤星病发生规律和生物学特性并筛选高效防治药剂,连续3年在四川省泸州市、凉山州、攀枝花市、广元市、宜宾市等5个主要植烟区对烟草赤星病发生情况进行调查,并在烟叶成熟期采集典型患病烟叶进行病原菌分离培养,通过宏观形态学、显微形态学及分子生物学鉴定其种类并测定菌落生长速率和萌发率,同时在烟田开展烟草赤星病高效防治药剂筛选。结果表明,5个烟区采集的赤星病样均属于链格孢属（Alternaria spp.）真菌,各烟区所采集分离的赤星病菌在SDAY培养基上菌落直径、产孢量和萌发率差异均不显著。5个烟区均发生烟草赤星病,整体发病规律为：每年6月底至9月初,烟田病情指数随着时间的推移逐渐增加,每年8月份,5个植烟区烟草赤星病病情指数显著高于7月份并趋于峰值。10%苯醚甲环唑水分散粒剂和40%菌核净可湿性粉剂对烟草赤星病均有较好的防治效果（防效均大于60%）。     

自配变色移膜革专用防霉剂性能评价试验

通过杀菌效果试验,理化性质检测,毒性、刺激性试验和耐药试验,评价了自配复合型变色移膜革专用防霉剂的综合性能。同时设计了几种乳油配方,并对由各配方在水中的分散性进行了评估。研究结果表明:该防霉剂高效、低毒、环保、经济,对变色移膜革具有良好的综合防霉性能;几种自制乳油配方在水中具有良好的分散性。     

基于大肠杆菌HT115合成dsRNA杀菌剂前体物质的研究

喷雾诱导基因沉默（spray-induced gene silencing,SIGS）基于RNA干扰（RNA interference,RNAi）,在体外合成靶标双链RNA（double-stranded RNA,dsRNA）并施用在附着病原菌的果蔬表面,通过dsRNA的跨界转运和对同源信使RNA（message RNA,mRNA）的特异性降解,实现对靶标基因的沉默,在果蔬采后病害防治领域具有很大潜力。但目前dsRNA的体外合成通常采用商业化的试剂盒,价格十分昂贵,阻碍了dsRNA杀菌剂的大规模应用。该文以工程菌-大肠杆菌HT115为宿主,建立能够合成靶向桃采后软腐病菌（匍枝根霉）β-1,3-葡聚糖合成酶dsRNA的合成体系,可实现靶标dsRNA的低成本量产。     

制革用新颖生态杀菌剂——小花“牛至”精油

小花牛至是土耳其一种特有的植物，将其叶及花冠，用蒸汽蒸馏即可得精油。精油的杀菌性能已为人所熟知。这是天然物质，且无诱变性。由于这些优点，有很多研究涉及多个领域（医药、食品工业等）。 本研究的目的在考察是否可能应用牛至精油于制革浸酸及鞣制工序以防止生霉。 在本研究中，将含TEMTB（2氰硫基-甲硫基苯噻唑）及N-OITZ（N-辛基噻唑咻酮）的商品杀菌剂作对比试验用。在进行微生物测试时，研究了精油及杀菌剂（商品）对黑曲霉菌、异间连孢霉菌、紫红青霉菌、绿木霉菌的作用。这些都是对制革造成危害的霉菌。研究结果表明，牛至精油的抗霉能力，用量增加时，作用也更大。对比试验的结果，革用精油处理后，抗霉性能优于现商品杀菌剂。     

Comparative Study of Monoclonal and Recombinant Antibody-Based Immunoassays for Fungicide Analysis in Fruit Juices

A comparative study of the analytical performance of enzyme-linked immunosorbent assays (ELISAs), based on monoclonal and recombinant antibodies, for the determination of fungicide residues in fruit juices has been carried out. To this aim, three murine hybridoma cell lines secreting specific monoclonal antibodies against (RS)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetrafluoroethyl ether (tetraconazole), 2-(4-triazolyl)benzimidazole (thiabendazole), and (RS)-1-(β-allyloxy-2,4-dichlorophenylethyl)imidazole (imazalil) were used as a source of immunoglobulin gene fragments for the production of single-chain variable fragment (scFv) and fusion scFv-pIII recombinant antibodies in Escherichia coli. Selected recombinant antibodies displayed cross-reactivity profiles very similar to those of the parent monoclonal antibodies. Imazalil and tetraconazole recombinant antibodies showed one order of magnitude lower affinity than their respective monoclonal antibodies, whereas the thiabendazole recombinant antibodies showed an affinity similar to that of their parent monoclonal antibody. On the other hand, scFv-pIII fusion fragments showed similar analytical properties as, and occasionally better than, scFv recombinant antibodies. Finally, ELISAs developed from each antibody type showed similar analytical performance when applied to the analysis of the target fungicides in fruit juices.     

田间烟草赤星病菌繁殖代数与其对杀菌剂敏感性的关系

为合理用药、提高防效,探讨了田间烟草赤星病菌繁殖代数与其对杀菌剂敏感性的关系。室内进行了在田间烟草不同生长时期采集的6个赤星病菌株对杀菌剂敏感性测定,并用聚类分析方法比较了各菌株对杀菌剂敏感性差异。结果表明,不同时期采集的不同繁殖代数烟草赤星病菌株对"菌核净"的敏感性差异显著,其中4号菌株对"菌核净"最不敏感,EC50为193 3644mg/L,已产生一定的抗药性,其次为1号菌株,EC50为102 3738mg/L,对"菌核净"最敏感的是2号和3号菌株,EC50分别为42 0390和58 4109mg/L。表明不论前期还是后期采集的菌株都有对"菌核净"敏感和不敏感的,烟草赤星病菌株的繁殖代数与其对"菌核净"的敏感性无一定规律性。从聚类分析树状图也可以看出这种敏感性的差异情况。     

分子印迹固相萃取-高效液相色谱法分析食品中3种三唑类杀菌剂残留

为建立分子印迹固相萃取-高效液相色谱法检测食品中3种三唑类杀菌剂残留的方法,分别以联苯三唑醇、烯唑醇和腈菌唑为模板分子,α-甲基丙烯酸(MAA)和丙烯酰胺(AM)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,采用本体聚合法合成分子印迹聚合物。将制得的联苯三唑醇、烯唑醇和腈菌唑聚合物按质量比1∶1∶1混合,制成固相萃取柱,用于样品的前处理,采用高效液相色谱法检测。结果表明,联苯三唑醇、烯唑醇和腈菌唑在5 min内实现基线分离。在低和高浓度添加水平下,平均回收率在90.6%~92.7%之间,RSD在1.2%~3.3%之间(n=5),联苯三唑醇的检测限为0.1μg/g,烯唑醇和腈菌唑的检测限为0.2μg/g。该方法分析速度快,灵敏度高,精密度好,适合于同时检测食品中联苯三唑醇、腈菌唑和烯唑醇3种三唑类杀菌剂残留。     

大理州烟草黑胫病菌对烯酰吗啉的敏感性测定

采用含药平板法建立烟草黑胫病菌对杀菌剂烯酰吗啉的敏感基线,并测定了2013年从云南省大理州各烟区分离纯化的烟草黑胫病菌菌株对烯酰吗啉的敏感性。结果显示,烟草黑胫病菌的敏感基线为1.4656 μg/mL;68个田间菌株对烯酰吗啉的EC₅₀值在0.5857~2.5254 μg/mL之间,平均为1.1118 μg/mL。表明烯酰吗啉对烟草黑胫病菌的活性较高,大理州烟草黑胫病菌的抗药性风险较低。烯酰吗啉可用于大理州烟草黑胫病的有效防控,但应与其他杀菌剂进行合理的轮换使用。     

QuEChERS-超高效液相色谱-串联质谱法快速检测果蔬中35种甲氧基丙烯酸酯类和三唑类杀菌剂的残留量

目的 建立一种测定水果蔬菜中甲氧基丙烯酸酯类和三唑类35种杀菌剂残留量的超高压液相色谱-串联质谱检测方法。方法 样品用乙腈提取和QuEChERS方法净化, 采用C18柱子以0.2%甲酸溶液-乙腈作为流动相进行梯度洗脱, 质谱(ESI+)电喷雾正离子模式电离,采用多离子检测模式(MRM)对35种杀菌剂的定量离子和定性离子进行监测。结果 本方法中35种杀菌剂在1.0~50 μg/L的浓度范围内线性关系良好, 相关系数r2为 0.9990~0.9998;在0.005、0.050、0.100 mg/kg添加水平的回收率为61.8%~123%, 方法定量限为1.0~1.5 μg/kg。 结论 该方法快速、环境友好、准确、灵敏, 适合水果蔬菜甲氧基丙烯酸酯类和三唑类杀菌剂残留的检测。     

分子印迹固相萃取膜-高效液相色谱法检测粮谷中的三唑类杀菌剂

本文建立了同时分离检测粮谷样品中4种三唑类杀菌剂的分子印迹固相萃取膜-高效液相色谱法。采用自制的联苯三唑醇分子印迹固相萃取膜对粮谷中的联苯三唑醇、三唑酮、烯唑醇和戊唑醇残留进行分离富集,并采用高效液相色谱法测定其在粮谷样品中的残留。试验对淋洗剂、洗脱剂的种类和用量以及检测条件进行了优化。以5 m L水为淋洗剂,3 m L甲醇为洗脱剂,使用C18色谱柱,以甲醇-水(体积比为82:18)溶液为流动相,紫外检测波长为210 nm,外标法定量。结果表明,4种杀菌剂平均回收率在84.2%~98.1%之间,相对标准偏差(RSDs)在1.2%~2.7%之间(n=5)。该分子印迹固相萃取膜不仅对样品净化效果好,而且对4种杀菌剂特异吸附能力强。该方法能高效、快速、灵敏检测粮谷样品中三唑类杀菌剂。     

高效液相色谱-荧光法同时检测葡萄汁中3 种苯并咪唑类农药

建立同时检测葡萄汁中3 种苯并咪唑类农药（多菌灵、噻菌灵、麦穗宁）残留的分散固相萃取处理结合高效液相色谱方法。样品经乙腈提取,无水MgSO4和NaCl盐析后,用N-丙基乙二胺固相萃取材料分散净化,然后采用高效液相色谱-荧光检测器根据不同的保留时间选择相应的最佳检测波长同时测定3 种农药。通过对提取盐、净化剂、色谱条件的优化,方法的加标回收率在85%～115%之间,相对标准偏差在1.95%～9.75%之间,多菌灵、噻菌灵和麦穗宁检出限分别达到17.60、1.20、0.06 μg/L。该方法简单、准确、重复性良好,满足葡萄汁中多种苯并咪唑类农药残留同时分析的需求。     

温控辅助离子液体分散液液微萃取-高效液相色谱检测果汁中杀菌剂残留

建立温控辅助离子液体分散液液微萃取结合高效液相色谱-二极管阵列检测器法检测果汁中7 种杀菌剂农药残留的新方法。对影响萃取效果的因素萃取剂和分散剂类型及体积、溶解温度、萃取时间和离心时间进行优化。在优化后的方法条件下,7 种杀菌剂富集倍数可达64～101;方法检出限在4.3～13.0 μg/L之间;在0.02、0.05 mg/L和0.10 mg/L三个水平下加标,果汁（苹果汁、梨汁、葡萄汁、桃汁和橙汁）的平均加标回收率在70.0%～116.2%范围内,相对标准偏差均小于9.8%,能满足多种果汁中杀菌剂农药多残留检测的要求。     

Determination of Triazole Fungicide Residues in Fruits by QuEChERS Combined with Ionic Liquid-Based Dispersive Liquid-Liquid Microextraction: Optimization Using Response Surface Methodology

Food Analytical Methods - A rapid, efficient, and environmentally friendly method using quick, easy, cheap, effective, rugged, and safe (QuEChERS) combined with ionic liquid-based dispersive...     

世界油料、油脂供需及贸易格局分析

总结近几年世界油料、油脂生产、消费以及贸易格局变动特征,分析了大豆、油菜籽、花生、棕榈油、大豆油、菜籽油及葵花籽油的主产国和需求国之间供需贸易情况,以及未来世界油脂市场供求贸易关系的演变趋势。分析表明:未来发展中国家对油料、油脂市场的影响日趋显著;从全球视角来看,油料主要供给国之间以及主要需求国之间存在相互竞争关系,具体表现为供给国供应能力和需求国购买力相互间的权衡。     

Composition of meat and offal from weaned and fattened rabbits and results of stereospecific analysis of triacylglycerols and phosphatidylcholines

BACKGROUND: Rabbit meat has excellent nutritive properties. The purpose of this study was to characterize rabbit meat and offal; in particular, the lipid fraction was studied in order to evaluate total and positional fatty acid (FA) compositions of triacylglycerol (TAG) and phosphatidylcholine (PC) fractions. Eight samples of weaned and eight of fattened rabbits were considered. RESULTS: Fattened rabbit meat contained slightly higher protein percentage content (P < 0.05) in comparison to weaned (20.1% versus 18.0%). Calcium content was higher in meat than in offal, unlike sodium, iron, zinc, manganese and copper. The cholesterol content in offal was much higher than in meat. FA profiles of total lipid showed a high percentage of unsaturated fatty acids and an n‐6/n‐3 ratio of 10.3 for fattened rabbit meat. Stereospecific analysis of TAG and PC was carried out on an eight‐sample pool of each meat and offal from weaned and fattened rabbits. In all samples the sn‐2‐position was prevalently esterified with oleic and linoleic acids in TAG, with polyunsaturated fatty acids in PC. CONCLUSION: Lipids from rabbit meat presented higher content of monounsaturated FA and lower n‐6/n‐3 ratio in comparison to offal, which was characterized by higher cholesterol and mineral levels. Copyright © 2011 Society of Chemical Industry