西安市蔬菜中重金属污染分析评价

采用原子吸收光谱法和原子荧光光度法,测定了西安市郊区10种蔬菜40个样品中汞、砷、铅、铬和镉的含量;并以国家标准(GB18406.1-2001)为依据.对蔬菜重金属污染状况进行分析评价,以明确西安市蔬菜中重金属污染状况.结果表明,西安市10种蔬菜总体合格率为83%,铅是蔬菜中的主要污染元素,在测定的10种蔬菜中普遍存在,总体超标率为77.5%;汞和铬只在芹菜和茼蒿上出现污染,总体超标率分别为10%和2.5%;叶菜类蔬菜铅污染>茄果类蔬菜;砷和镉含量均末超过国家标准规定,合格率为100%.铅的污染程度按蔬菜种类依次为:生菜>茼蒿>韭菜>茄子>芹菜>豇豆>青椒>油麦菜>西红柿>黄瓜,按不同生产区域依次为:西郊>北郊>东郊>南郊.     

基于活性氧自由基水平评价蔬菜重金属污染

蔬菜细胞中活性氧自由基水平处于一定范围内,而蔬菜一旦受重金属污染,活性氧自由基水平将发生改变.本文采用2＇,7＇-二氯荧光黄双乙酸酯标记蔬菜叶片细胞内活性氧自由基,激光扫描共聚焦显微镜技术分析蔬菜受重金属污染后活性氧自由基荧光强度的变化.结果表明,不同浓度镉、铅、汞离子（0、25、50、100 mg/L）作用芹菜、菠菜和油菜后,蔬菜叶片中活性氧自由基荧光强度均呈上升趋势,基于活性氧自由基水平的升高可判断蔬菜是否受重金属污染.本研究建立了基于活性氧自由基水平的蔬菜重金属污染评价方法,进一步为蔬菜的监管提供方法学和技术理论基础.     

武汉市蔬菜重金属污染现状的调查与评价

通过对武汉市6种蔬菜的供食部位及所对应的土壤中重金属Hg(汞)、Cu(铜)、Pb(铅)、Cd(镉)、Cr(铬)、Zn(锌)、As(砷)含量及分布特征进行了检测,结果表明:Pb、Cr是武汉市蔬菜中主要的污染元素;Hg、Cd只在个别叶菜类上超标;Zn、Cu、As无超标样。在所时应的土样中,普遍存在污染的是Cd,其它6种重金属元素均未超标。     

湘南某矿区蔬菜中Pb、Cd污染状况及健康风险评估

通过采集湘南某矿区周边农田中种植的蔬菜和对应耕作层土壤样品,探究了农田蔬菜Pb、Cd的污染状况,蔬菜和土壤重金属含量之间的相关性,蔬菜中重金属对人体的健康风险。结果表明:(1)污染区土壤重金属污染非常严重,叶菜类蔬菜重金属超出了食品卫生标准限值,但是果菜类蔬菜中重金属没有超出食品卫生标准限值。(2)不同蔬菜不同器官所含Pb、Cd有明显差异;不同种类蔬菜Pb、Cd含量不同,一般是叶菜类果菜类;同种蔬菜不同部位重金属含量的顺序也不同,一般为根茎叶果,或根叶茎果。(3)二类蔬菜中重金属Pb、Cd的富集系数顺序为叶菜类果菜类。(4)蔬菜中Pb、Cd含量与土壤中相对应元素含量均无显著相关性。(5)就农产品安全性而言,果菜类蔬菜比叶菜类蔬菜更适合在此矿区栽培。     

城市蔬菜的重金属污染及其对策

通过对我国主要城市已开展的蔬菜重金属污染调查的回顾 ,对城市蔬菜的重金属污染现状的评价进行了比较 ,综合分析了造成城市蔬菜重金属污染的成因 ,并提出了几点降低和控制城市蔬菜重金属污染的对策。     

铅、镉在蔬菜中的累积特性及对蔬菜生长的影响

采用不同浓度原位污染土盆栽试验,研究铅(Pb)、镉(Cd)在8种蔬菜中的累积规律及对蔬菜生长的影响,揭示蔬菜-土壤铅、镉含量相关关系,提出8种蔬菜的土壤铅、镉安全临界值。结果表明:油菜、甘蓝长势均好,生长未受抑制,其他几种蔬菜随铅、镉浓度的增加,生长受到不同程度抑制;铅、镉复合污染对8种蔬菜的生长抑制程度为芹菜莴苣胡萝卜豇豆辣椒番茄甘蓝、油菜,与蔬菜累积铅、镉能力一致;芹菜-土壤铅、镉含量呈显著线性相关(R2=0.923,0.956);土壤铅安全临界值为叶菜类(甘蓝、油菜)根茎类(莴苣、胡萝卜)豆类(豇豆)芹菜和辣椒,番茄土壤铅安全临界值待定;8种蔬菜土壤镉安全临界值相同。     

果实类蔬菜套袋技术效果评价

田间系统研究了不同袋型的套袋效果及不同果实类蔬菜最佳套袋的时期。室内测定分析了套袋果实蔬菜的营养物含量及农药残留量。结果表明：黄瓜、番茄、西葫芦、茄子套膜袋均有显著的增产效果,分别为16．4％、11．6％、10．1％、13．7％。套纸袋除番茄外亦均有明显增产效果。套膜袋VC含量增加22．0％～152．9％。畸形瓜(果)降低11．5％～32．3％,袋体有效阻隔了化学农药对果实类蔬菜直接接触污染。套膜袋黄瓜、番茄、茄子、西葫芦中农药残留量分别降低83．3％、84．5％、79．7％、85．7％,套纸袋依次降低73．2％、79．9％、70．9％、83．1％。套袋栽培协调了病虫防治与绿色食品蔬菜生产的矛盾。     

无公害蔬菜营养与施肥研究进展

本文综述了无公害蔬菜定义、卫生评价标准及生产环境评价标准。对无公害蔬菜生产中常用的氮肥在土壤中转化、种类和形态、用量和时期与硝酸盐关系,过量氮肥对蔬菜体内硝酸盐累积影响,对地下水质污染和人体健康的影响,磷肥过量引起流失造成水体富营养化和磷肥中镉对土壤生态环境污染的影响,以及畜禽粪肥、城市垃圾和污泥堆肥对蔬菜品质及环境影响进行了评述。对近二十年来土壤栽培条件下应用于无公害蔬菜营养诊断与平衡施肥研究的     

天津市武清区农田土壤和蔬菜中重金属污染特征及来源解析

为评价中国北方典型农田土壤和蔬菜重金属污染特征,从天津市武清区分别采集45个农田表层土壤及对应的叶类蔬菜、32个农用畜禽粪便样品和4组土壤剖面,测定了Cd、Cr、Cu、Ni、Pb和Zn共6种重金属的含量和形态,并利用相关性分析和主成分分析判断土壤中重金属污染的可能来源。结果表明:表层土壤6种重金属的累积程度依次为CdCrCuZnPbNi,其中26.7%的Cd超过了土壤环境质量二级标准(GB 15618—2018);叶类蔬菜根部存在重金属累积(尤其是Cd),但蔬菜叶片中并不存在重金属超标;研究区所施用的畜禽粪便中Cd的超标率为16%(参照NY 525—2012),其长期施用会造成表层土壤中重金属的累积;同时,表层土壤中高的可交换态Cd、Cu和Zn会增加作物吸收土壤中重金属的风险,是造成当地叶类蔬菜根部和叶片中重金属累积的原因之一。结合主成分分析结果:Cr和Ni主要来自于成土母质; Zn主要受农业活动影响,如畜禽粪便的施用; Cd和Pb主要受工业活动影响; Cu为复合污染,受工业和农业活动共同影响。综上所述,研究区土壤和畜禽粪便中存在Cd超标现象,虽然目前蔬菜叶片中重金属未超标,但应该注意控制或减少农业和工业污染对蔬菜地重金属的影响,以确保农田土壤和蔬菜的安全。     

山西森林蔬菜资源及其开发利用研究

山西森林资源丰富,植物组成多样。通过野外调查和数据分析,山西森林蔬菜有426种,分为6类,隶属于92个科中的260个属,其中叶菜类多达215种,茎菜类最少为14种,6类森林蔬菜的数量由多到少依次为叶菜类>果菜类>花菜类>根菜类>菌藻类>茎菜类。在此基础上,评价了山西森林蔬菜的种类、特色、营养价值及药用价值等,并对其开发利用提出了建议。     

甘蓝薄翅螟的生物学特性

甘蓝薄翅螟Crocidolomia pavonana(Fabricius)是广西南宁新发现的一种蔬菜害虫。该虫在当地年发生13个世代,卵期2.5~6.5d,幼虫期8.0~13.0d,世代历期18~39.5d。整年均可发生为害,为害峰期在4~6月。主要寄主是甘蓝、白菜、芥菜、萝卜、油菜等。幼虫共4龄,以幼虫咬食寄主的叶片、嫩茎和花,老熟幼虫在土表下化蛹。     

Characterization of multiple-antimicrobial-resistant Salmonella enterica Subsp. enterica isolated from indigenous vegetables and poultry in Malaysia

Aims: The aims of this communication were to study characterization of serogroups among Salmonella isolates and the relationship of antimicrobial resistance to serogroups. Multiple antimicrobial resistance (MAR) was performed on 189 Salmonella enterica isolates associated with 38 different serovars that were recovered from poultry and four types of indigenous vegetables. Methods and Results: Disc diffusion analysis was performed with a selection of 10 different antimicrobial agents. Isolates recovered from indigenous vegetables showed 100% (134/134) resistant to erythromycin and followed by 42%, 34%, 19% for tetracycline, streptomycin and trimethroprim‐sulfamethoxazole respectively. In general, 90·1% (50/55) and 56·7% (76/134) of Salmonella isolated from poultry and indigenous vegetables, respectively, exhibited MAR index more than 0·2. Conclusions: Characterization of Salmonella isolates based on the MAR results indicated that poultry still remains as the main reservoir for multi‐drug‐resistant Salmonella. Four isolates from the indigenous vegetables showed the highest MAR index in this study. Further investigations need to be conducted to determine if Salmonella isolates recovered from indigenous vegetables were gaining more antimicrobial resistance. Significance and Impact of the Study: The study enabled us to determine antimicrobial patterns and trends in Salmonella from poultry and indigenous vegetables in Malaysia.     

Outdoor cultivation of sea vegetables

Summary The outdoor cultivation of sea vegetables is carried out on a large scale in the Orient, mainly in Japan, China, Taiwan, Korea and the Philippines. Food crops are the most important among the sea vegetables cultivated, with Porphyra and Undaria being the more important in Japan and Laminaria in China. Eucheuma, an industrial crop containing the phycocolloid carrageenan, is cultivated in wide areas of the Philippines. The cultivation of the major food crops, which developed quickly over the past 30 years, is largely based on the results of research, especially with regard to seeding procedures, which have reached a certain level of sophistication.The major crops of sea vegetables are cultivated attached to ropes or nets located in a suitable site and habitat. Crops of limited economic value, however, are still cultivated by the old, primitive method of planting on stones on the ocean bed and other similar means. The location and timing of farming are selected with regard to the requirements of the plants for light, temperature, water movement, exposure to air (for the intertidal species),etc. Cultivation of seeding material of the three food crops and seeding of ropes and nets is carried out indoors under more or less controlled conditions. When the sporelings become established they are transferred to cultivation grounds in the ocean. When the plantlets grow too densely (in Laminaria) they have to be separated and replanted at the correct distances. This is done several weeks after transplantation to the ocean, when they are large and sufficiently strong. Eucheuma and other industrial crops are propagated vegetatively, using cuttings and fragments as planting material. Where seawater is lacking in nutrients, fertilizers are applied to guarantee a higher yield. The harvest is carried out manually, except for Porphyra, for which mechanical harvesters are used. Sea vegetables are attacked by pathogens that may cause severe damage to the crops. Diseases caused by improper growing conditions are also known. Grazers may also inflict losses. In all major crops the strains cultivated have been selected. In a few cases hybridization and other genetic techniques have been used to obtain domesticated varieties that can grow and yield far beyond the limits of their wild-type parents.Despite the fact that some mechanization has been introduced into the cultivation of sea vegetables, it is still by and large a highly labor-intensive enterprise. Nevertheless, it competes well with terrestrial crops in the Orient from the economic point of view.Interest in the cultivation of sea vegetables is widespread in the West and much experimental work aimed at its materialization has been underway during the lastca. twenty years.     

即食型脱水蔬菜杀青、漂烫工艺初步研究

针对不同的即食型脱水蔬菜原料特性,进行前处理漂烫工艺研究。对蔬菜漂烫过程中营养成分的损失、酶活性的变化、褐变、护绿等多种因素进行综合考察,以获得了即食型脱水蔬菜漂烫最佳工艺参数。     

黄曲条跳甲为害下十字花科蔬菜可溶性糖含量的动态变化

采用蒽酮比色法测定了十字花科蔬菜上黄曲条跳甲Phyllotreta striolata（Fabricius）不同危害程度下叶片可溶性糖含量的变化。结果表明黄曲条跳甲的为害显著影响十字花科蔬菜的可溶性糖含量。萝卜接虫2d,甘蓝接虫4d、12d,芥蓝接虫2d、8d、12d,白菜、芥菜、菜心接虫2d、4d、6d、8d、10d、12d时,健叶、轻度为害叶、中度为害叶、重度为害叶的可溶性糖含量均低于对照。但萝卜接虫4d、6d时,中度为害叶、重度为害叶的可溶性糖含量高于对照,4d时,重度为害叶升高28．65％,甘蓝接虫2d时,可溶性糖含量分别升高18．70％、24．40％、30．88％、30．50％,芥蓝接虫2d、4d时,轻度为害叶、重度为害叶的可溶性糖含量均高于对照。十字花科蔬菜可溶性糖含量的变化是植株对害虫胁迫的一种响应。     

湘北地区野生蔬菜资源的开发利用

本文报道了湘北地区的野生蔬菜种类 ;共计 2 6科 4 2属 4 9种。并探讨了湘北地区野生蔬菜的开发利用前景     

我国野生蔬菜资源的开发利用研究

对我国野菜资源利用的历史和现状、野菜营养价值和重要性、野菜的加工和商品化开发进行了阐述,并针对我国野菜研究与开发中的存在问题提出了对策。     

Preservation of vegetables by microbial activity and radiation

Two locally-produced seasonal vegetables, carrot and patol, were preserved in brine, with and without radiation, with marked changes in their properties as foods and their microbiology. The treated vegetables could be preserved, at optimum salt and irradiation levels, for up to 60 days without becoming unacceptable in terms of appearance, texture, flavour and taste. The optimum salt concentrations for preservation of carrot and patol were 2% (w/v) and 3% (w/v), respectively. The microbial load initially showed an upward trend and then declined after 5 to 10 days of storage. Lactic acid bacteria predominated in treated vegetables.     

Survival of Salmonella enteritidis and Listeria monocytogenes on salad vegetables

The influence of initial head-spaces of air – 4.9% CO₂/2.1% O₂/93% N₂ and 5% CO₂/5.2% O₂/89.8% N₂ – on Salmonella enteritidis and Listeria monocytogenes, and on microbial association with shredded carrots and lettuce was studied at 4 °C. Both these pathogens survived but did not grow in any vegetable regardless of the packaging system used. Total viable count, lactic acid bacteria and pseudomonads were also monitored. Lactic acid bacteria were the predominant organisms in all samples. The pH dropped significantly during the storage of vegetables.     

茄科蔬菜花青素苷分子调控研究进展

花青素苷是一种分布广泛的水溶性色素,不仅赋予了果实多彩的外表,还是天然食用色素的重要来源。近年来有关茄科蔬菜花青素苷的研究逐渐增多,文中从花青素苷结构及其生物合成途径、茄科蔬菜中花青素苷合成代谢的结构基因和调节基因、影响合成的环境因素等方面进行回顾和总结,为进一步阐明茄科蔬菜花青素苷的合成及调控机理、更好利用花青素苷进行果色品质育种的创新提供一些参考。