臭氧去除果蔬中农药残留研究进展

水果、蔬菜中农药残留的清洗去除研究是进一步提升食品安全的保证。臭氧处理技术是去除农药残留的常用方法之一。本文主要介绍了用于去除水果蔬菜上农药残留的臭氧处理技术,包括:臭氧产生方式、应用形式以及臭氧与其他方法联合处理技术的应用,综述了影响农药残留去除效果的因素,也介绍了臭氧去除农药残留的同时对果蔬外观、营养等影响,进一步探究了臭氧去除农药残留的作用机制和应用价值,旨在为臭氧清洗技术用于去除果蔬农药残留的研究提供理论和应用参考。     

植物内生菌抗菌活性物质及其在果蔬采后保鲜中的应用进展

植物内生菌是寄生在植物组织中的一大类群特殊微生物,过去长期被忽略。然而越来越多的研究表明,植物内生菌是新型抗菌药物的宝贵资源,其代谢产物中存在一系列具有多样性结构的抗菌活性化合物。本文对近年来植物内生菌产生的抗菌活性物质及其抗菌效果进行了综述,简要介绍了植物内生菌在果蔬采后保鲜中的应用,同时总结了植物内生菌抗菌活性物质在当前实际研究中所遇到的问题。     

臭氧消解水中残留农药的试验研究

本文介绍了用臭氧消解水中残留农药的试验方法、结果及臭氧浓度与农药浓度之间的变化关系。     

美国EPA农药登记残留试验样品储藏稳定性资料要求概述

本文概述了美国环保局关于农药登记残留储藏稳定性试验的有关要求,包括基本要求、残留储藏稳定性试验要求、试验结果的使用、试验报告的编写等。希望对我国制定相关技术规范有所借鉴。     

美国EPA农药登记残留试验中样品储藏稳定性试验

<正>农药残留稳定性数据在农药登记残留试验中占有重要地位,由于残留试验样品采收后会在冰箱中存放较长时间,因此,样品储藏期间农药在样品中的稳定性研究对农药残留检测结果判定具有重要意义。我国一直缺少此方面的规定,导致农药残留基础研究数据缺乏,现翻译美国EPA农药登记残留样品储藏稳定性试验准则,供读者参考。OPPTS 860.1380样品储藏稳定性数据1范围1.1适用性该导则的目的是满足联邦杀虫     

农药残留现状及不同处理方式去除果蔬中农药残留的研究进展

随着国家政策优化,农药的使用量日渐减少,但是农药残留仍是严峻的问题。清洗等是普通家庭中去除果蔬农药残留的主要手段,研究不同家庭处理方式对农药残留去除效果有着重要的意义。本文对国内残留现状和不同处理方式进行了介绍,包括普通清洗方式、电解水清洗、臭氧清洗、超声清洗,同时也介绍了不同果蔬、不同农药种类清洗方式的较优条件,为普通家庭选择清洗方式提供了参考。     

快速溶剂萃取/气相色谱测定果蔬中有机氯农药残留的研究

建立了使用快速溶剂萃取（ASE）技术提取,毛细管柱为分离柱,以电子捕获检测器检测,用气相色谱法同时测定果蔬中15种有机氯农药的残留量.与国标法--振荡萃取法（MSE）相比,在保证足够的准确度的前提下,具有前处理时间短、所用试剂少的特点.用该方法测试的结果表明,在5种果蔬中填加一定浓度的待测物时,各种待测物的回收率均在85.7%～108.5%之间;相对标准偏差（RSD）为1.9%～9.5%（6次测定平均值）;最低检出限为1.1～20μg/kg.之间,结果表明,使用ASE萃取果蔬中有机氯农药符合国标规定的农药残留检测的需要.     

豇豆被查出含禁用农药 如何避免果蔬残留农药

事例1：武汉市场 2月22日,海南产豇豆已经通过盘溪批发市场流入武汉市,为确保安全,市场上已紧急下柜。据查,海南豇豆使用禁用农药,武汉宣布3个月内禁止销售海南豇豆。     

臭氧水对黄瓜和青菜中6种有机磷农药残留的去除效果

考察了臭氧水浸泡处理对黄瓜和青菜上6种有机磷类农药残留的去除效果。发现臭氧水浸泡的去除效果优于自来水处理,在通臭氧30 min后,其对青菜和黄瓜中乙酰甲胺磷、二嗪磷、马拉硫磷、毒死蜱、喹硫磷和三唑磷的总去除率分别为26.4%~65.2%和22.7%~75.4%,净去除率分别为6.8%~17.3%和4.4%~45.4%。对6种农药在臭氧水中降解速率的研究表明,臭氧处理对残留农药的去除效果与果蔬种类、处理时间及残留物种类有关。     

诱导抗性在果蔬采后病害防治中的研究与应用

 近年来,有关果蔬产品采后诱导抗性的研究较多,生物和非生物因子(如微生物、化学物质、物理因素以及天然物质等)都能够诱导果蔬产品采后的抗性。生物因子研究较多的是拮抗菌,许多生物拮抗菌都具有自生和诱导果实产生抗病相关酶活性的作用,可以有效抑制病原菌的生长。物理诱导主要包括γ-射线、离子辐射、紫外光照和热水处理等,热水浸泡柑橘果实能有效控制贮藏期间的腐烂;低剂量紫外光照射桃、芒果、草莓、葡萄和甜椒等果蔬产品可明显减轻采后病害。用于果蔬产品的化学诱导剂主要有β-氨基丁酸(BABA),苯丙噻重氮(ASM),水杨酸(SA),茉莉酸(JA)和茉莉酸甲酯(MJ)等。将SA与生物拮抗菌配合,可诱导甜樱桃果实过氧化物酶(POD),苯丙氨酸裂解酶(PAL)和β-1,3-葡聚糖酶的活性,提高果实贮藏期间的抗病性;ASM在开花前处理哈密瓜也具有一定的抗病诱导效果;用BABA处理葡萄柚后,能刺激果实伤口附近PAL活性增加,增强了果实对绿霉病菌侵染的抵抗力;作为植物生长调节剂的JA及其酯化物MJ,对植物抗病性也具有明显的诱导作用,JA和MJ被认为是植物在病原菌侵染防御反应中细胞信号转导的一种关键物质;用MJ处理采后的苹果和桃果实能增强贮藏期间的抗病性,其诱导强度与果实的成熟度密切相关;将钙盐与生物拮抗菌配合使用,也显著提高拮抗菌的抑病效果。另外,在自然抗病物质中壳聚糖的使用较多,用它处理柑橘果实可提高贮藏期间绿霉病的防治效果。这些生物和非生物因子的诱导抗性机理主要涉及到寄主的细胞结构变化和生理生化反应。本文较详细地论述了诱导果蔬产品采后抗性的因子及其可能的诱导机理。     

水果和蔬菜保鲜技术研究进展

介绍了目前国内、外一系列先进的水果和蔬菜保鲜技术,包括低温保鲜、化学保鲜、气调保鲜、涂膜保鲜、保鲜包装等;讨论了其优、缺点,并结合成本和安全性,分析了保鲜行业今后的发展趋势.     

Breakdown rates of dimethoate in fruit and vegetable dips

In order to determine the effect of pH and temperature on post-harvest dip solutions of dimethoate (500 mg litre^?1), the half-lives and pseudo first-order rate constants were calculated from measurements at pH 4, 6, 8, 10, 11.5, and at two temperatures 25 and 52°C. The half-lives ranged from 206 days to 39.3 min at 25°C, and from 5.6 days to 205s at 52°C; the rate constants ranged from 3.9 × 10^?8 s^?1 to 2.9 × 10^?4 s^?1 at 25°C, and from 1.4 × 10^?6 s^?1 to 3.4 × 10^?3 s^?1 at 52°C. The results show that the water used in dips should have a pH≤7. The addition of benomyl to the dip solutions at two concentrations (0.5 and 1.0 g litre^?1) had no effect on the half-lives and rate constants. The use of hard and salted waters in dips also showed no major effect. A formula was developed that gives the half-life of the dimethoate as a function of the pH and temperature.     

A field unit for determining dimethoate in fruit and vegetable dips

The concentration of dimethoate in post-harvest dips needs to be maintained at 400 or 500 mg litre^?1 to ensure that fruit fly are killed and also to keep residue levels below the MRL. A field unit which contains a colorimeter, a heating block and cooling positions has been evaluated. The diluted dip sample produces a colour with 4-(p-nitrobenzyl)pyridine after heating and the addition of tetraethylenepentamine. Precision of the unit was acceptable for a field test (repeatability of ± 10.1%) and there was reasonable agreement between determinations made on the unit and by an HPLC method for a range of dimethoate concentrations from 300 to 700 mg litre^?1. The unit can be used at the dip site and the analysis is completed in 30 minutes.     

QuEChERS-液相色谱-串联质谱法测定果蔬及其制品中噻霉酮残留

建立了QuEChERS-液相色谱-串联质谱(HPLC-MS/MS)测定果蔬及其制品中噻霉酮的分析方法。样品经含0.1%乙酸的乙腈提取,聚苯乙烯/二乙烯苯(PEP)和C18粉净化,以0.1%甲酸水溶液(含2 mmol/mL乙酸铵)和甲醇为流动相梯度洗脱,经C18色谱柱分离,正离子模式扫描,多重反应监测模式检测。以保留时间和特征离子对(母离子和两个碎片离子)信息比较进行定性,基质匹配外标法定量。结果表明:在10~500 ng/mL范围内,噻霉酮在黄瓜、葡萄、葡萄干、番茄酱、番茄和苹果6种基质中的决定系数(R2)均大于0.996;定量限(LOQ) (以S/N≥10计)为10.0 μg/kg,在10、20和100 μg/kg 3个添加水平下,平均回收率在80%~98%,相对标准偏差(RSD)在2.4%~13%。该方法高效快捷、准确度和精密度均符合农药残留检测要求。     

Model of the probability of pest transfer from imported fruit,cut flowers or vegetable produce

A Euphresco project funded by the UK and the Netherlands had the objective of developing practical tools to assess the risk of pest transfer to domestic production from an imported commodity and to help provide an improved rationale for reduced frequency of plant health inspection. A model is described which calculates the probability, following arrival, of the transfer of insect or mite pests up to and including first egg laying, from produce (cut flowers/branches, fruits and vegetables). In case studies, probabilities were estimated for alternative states of seven variables from which a joint probability of transfer was calculated. The probability estimates were subjective but informed estimates and the large differences between the cases examined may represent a more realistic picture of comparative transfer risk than more qualitative approaches.     

佳多频振式杀虫灯在上海地区蔬菜上控害应用的效益

长期以来在害虫防害手段上单纯地依赖化学农药,往往得不到很好的防治效果,相反却会引起越来越多的负面效应.     

Survival of Erwinia amylovora on pears and on fruit containers in cold storage and outdoors

The survival of Erwinia amylovora during cold storage or outdoors may be a relevant factor in the spread of fireblight. The survival of E. amylovora was studied in cold storage on pear fruits, on container materials and on packaging paper, and outdoors on wood (oak and poplar) and on polyethylene. The samples were contaminated with a bacterial suspension of a mutant strain, washed, concentrated by centrifugation, and the final concentrates were used for plate counting. In cold storage, reisolation from the calyx was successful even after 101 days, whereas on pear surfaces, it was unsuccessful after just 1 day. On oak and poplar wood, reisolation was obtained up to 77 days in cold storage for both types of wood, but only up to 27 and 55 days, respectively, outdoors. Reisolation from packaging paper in cold storage was successful up to 14 days. Reisolation from polyethylene outdoors was unsuccessful after 24 h. Survival curves were calculated for each material. On the basis of a model of inoculum transmission, and using the survival curves, a phytosanitary risk period for the different types of materials was estimated.     

无公害蔬菜基地建设和植保技术应用

无公害蔬菜基地建设 ,应对土、水、气环境和农药残留进行综合测定评价。在蔬菜种植过程中植保技术应力求安全、高效 ,以物理防治技术为主体 ,使用生物和低毒农药防治。产品进入市场应作农药残留定性检测和不定期田间抽样定量检测相结合 ,才能符合无公害蔬菜的生产要求