2001—2017年我国部分地区蔬菜中砷和重金属累积特征及膳食暴露风险

目的 探讨我国部分地区蔬菜中砷和重金属的累积特征,并分析潜在膳食暴露风险。方法 搜索论文数据库,收集2001—2017年发表文献中蔬菜铜(Cu)、铅(Pb)、镉(Cd)、铬(Cr)、砷(As)及汞(Hg)含量的数据,分析我国根茎类、叶菜类及茄果类蔬菜中As和重金属的污染特性,并采用美国环保署推荐的健康风险评价模型评估蔬菜中砷和重金属的膳食暴露风险。结果 3类蔬菜中Cu、Pb、Cd、Cr、As和Hg均呈非正态分布,变异系数均<10%。根茎类、叶菜类及茄果类蔬菜中Cd、As、Hg的含量均差异有统计学意义(P<0.05),叶菜类和茄果类蔬菜中Pb-Cr含量差异有统计学意义(P<0.05),但3类蔬菜中Cu含量均差异无统计学意义(P>0.05)。根茎类蔬菜中Pb、As和Hg的含量较高,叶菜类蔬菜中Cd含量较高。根茎类和叶菜类蔬菜中Pb-Cd及根茎类蔬菜中Pb-Cr相关性均较强(P<0.01)。3类蔬菜中Cu、Cd、Cr和As污染指数均在安全范围内,而根茎类和叶菜类蔬菜中的Pb和Hg均存在不同程度的污染,但基本属于轻度污染。根茎类和茄果类数值中As和重金属对成人和儿童的风险值均<1.0,但叶菜类蔬菜中Pb对成人和儿童的风险值的第95百分位数分别是1.780和2.020,表明叶菜类蔬菜中的Pb存在潜在的人体非致癌风险。结论 中国蔬菜中Cu、Cd、Cr、As和Hg整体污染较轻,但叶菜类蔬菜中Pb污染应引起重视。     

2016~2018年甘肃省市售蔬菜中铅汞污染状况及人体健康风险分析

目的 对甘肃省14个市州蔬菜中铅汞进行三年的采样监测,掌握铅汞重金属污染的基本情况并对人体健康风险进行了分析。方法 在全省14个市州共采集样品1213份,依据国标方法进行铅汞含量的测定,采用尼梅罗综合污染指数法对蔬菜中铅和汞污染程度进行评价,用目标危害指数法(THQ)和危害指数(HI)评价蔬菜中铅汞对成人和儿童的健康风险。结果 各类蔬菜中均检出了铅和汞,其中鳞茎类中的铅和茎类蔬菜中的汞检出率均达到了100%;块根和块茎类蔬菜铅的超标率为3.76%;汞含量除在茎类蔬菜中超标率为1.34%外,在其余种类中均未有超标。从铅汞的综合污染指数来看,除茎类蔬菜以外,其他都表现为Pb＞Hg,铅对蔬菜重金属污染贡献较大,其中瓜菜类和鳞茎类的铅含量综合污染指数分别为0.61和0.52,属于轻度污染;茄果类和块根块茎类蔬菜的铅含量综合污染指数分别达到了4.68和4.40,污染较严重。居民通过蔬菜摄入的铅汞的暴露风险儿童高于成人,但THQ和HI均小于1,对人体健康造成的影响不明显。结论 本次研究中甘肃省市售蔬菜中少数受到重金属铅的污染,其余蔬菜中铅汞含量对健康影响均在安全范围内。     

Model of vegetable freshness perception using luminance cues

Freshness perception is a quality discrimination process that influences our consumer choice and eating behavior, especially of highly perishable products such as vegetables. Previous research used photographic stimuli to investigate the relationship between luminance distribution and freshness perception for a cabbage leaf (C. Arce-Lopera, Masuda, Kimura, et al., 2013) and a strawberry (Carlos Arce-Lopera, Masuda, Kimura, Wada, & Okajima, 2012). In this study, the luminance and chromatic information of the freshness degradation process of four different vegetables (cabbage, strawberry, carrot and spinach) was recorded in a temperature, humidity and light controlled environment. However, instead of a camera, a 2D luminance and chromaticity analyzer (TOPCON UA1000) was chosen as the measurement equipment. Then, using a color management system to guarantee the exact reproduction of the recorded luminance and chromatic data of the real objects, a color and a grayscale version of the stimuli was created. Subsequently, those pictures were randomly presented to subjects who had to rate their perceived freshness using a visual analog scale. The achromatic results did not differ from the chromatic ones suggesting that luminance information is sufficient to enable an accurate estimation of vegetable freshness. Additionally, the original images were digitally manipulated only by modifying their luminance distribution and keeping their color information intact. When the resulting images were presented, using the same psychophysical experimental setting, the results showed that the perceived freshness also changed concordantly with the changes on the asymmetry of the luminance distribution. Finally, a model for vegetable freshness perception that utilizes only luminance cues is presented.     

Results from the monitoring of pesticide residues in fruit and vegetables on the Danish market, 1998?99

The objective of the Danish pesticide monitoring programme for fruit and vegetables was to check for compliance with the maximum residue levels in foods and to monitor the residue levels to assess the pesticide exposure of the Danish population. Sampling plans were designed based on previous findings and on food consumption data. Approximately 60% of the samples were selected on the basis of positive findings in samples from the previous 5 years. The remaining samples reflected the pattern of food consumption in Denmark. In addition, a rolling programme is maintained for commodities with a low consumption and no detected residues. Within each commodity, the sampling was random. Samples (n = 4150) of mainly fresh, conventionally grown fruit and vegetables were taken throughout the chain of suppliers including foodprocessing companies. Of the samples, 3% were frozen products and 2% were organically grown. Of the samples, 35% were of Danish origin, with 65% originating from other countries. Three accredited laboratories performed analyses of the samples using capillary gas chromatography, liquid chromatography and spectrophotometric methods. Results were registered online into a central database. Residues were found in 54% of the samples of fruit but only in 13% of the vegetables. Residues above the MRL were found in 4% of all samples of fruit and in 1% of vegetables.     

Catalytic determination of traces of oxalic acid in vegetables and water samples using a novel optode

A new optode has been introduced for determination of oxalic acid. The optode sensing reagent is Victoria blue 4R which is immobilized on triacetylcellulose membrane. This reagent could be oxidized by dichromate in acidic media resulting in decoloration of the membrane. Oxalic acid has a strong catalytic effect on this reaction. The difference in absorbance of the immobilized form of Victoria blue 4R at 615 nm between uncatalyzed and catalyzed reactions (ΔA) is directly proportional to the concentration of oxalic acid. Oxalic acid can be determined in the concentration range of 2–180 μg ml⁻¹. The effect of different possible interfering species has been examined and was shown that the optode has a very good selectivity. The optode has been applied for the determination of oxalic acid in different real samples such as spinach, beet root, mushroom and river water with excellent recoveries.     

北京市蔬菜硝酸盐和亚硝酸盐污染状况评价

为了解北京市蔬菜中硝酸盐和亚硝酸盐的污染情况 ,于 2 0 0 3年 4月～ 8月从北京 15个菜市场采集应季蔬菜样品 ,共 4 0个品种 4 44份样品 ,用国标法 (GB T 5 0 0 9 33— 2 0 0 3)分析蔬菜中的硝酸盐和亚硝酸盐的含量。结果显示 :检测样品中 ,污染程度严重的占 33 1% ;中、重度污染的占2 3 6 % ;轻度的占 4 3 2 % ;硝酸盐的含量依次为绿叶菜类 >白菜类 >根茎类 >瓜茄类 >葱蒜类 >豆类 >果类 >水生植物类 ,但同一类蔬菜不同品种的硝酸盐的含量差别较大 ,从几倍到几十倍 ;同一品种的蔬菜中硝酸盐含量差别也很大 ,可能与产地、生长条件不同有关。蔬菜中亚硝酸盐含量相对较低 ,其含量与蔬菜的新鲜程度有关。研究结果提示需要制定限量标准 ,加强监督管理     

2001年我国部分蔬菜和肉类污染状况调查及分析

为了解我国蔬菜和肉类污染的状况 ,受卫生部和国家三绿工程办公室委托 ,我们于 2 0 0 1年秋季在全国 14个城市采集了 6种蔬菜 10 8份样品和 30份猪肉及 15份鸡肉进行了有关污染物的污染状况调查。监测指标有铅、砷、甲胺磷和氯霉素等。结果发现所检的 4 5份肉的铅、砷和氯霉素全部符合国家标准 ,10 8份蔬菜中有一份铅超标 ,砷含量全部合格 ,但是发现蔬菜中存在滥用剧毒农药甲胺磷的情况 ,蔬菜中甲胺磷的平均检出率为 12 % ,检出率最高的为卷心菜 2 7 7%。     

北京市春季蔬菜硝酸盐含量测定及居民暴露量评估

为了解北京市春季蔬菜中硝酸盐污染及居民硝酸盐暴露情况,于2006年3-5月从北京市16个菜市场采集应季蔬菜7大类26个品种341份样品,用国标法(GB/T5009.33—2003)分析蔬菜中的硝酸盐含量。随机抽取北京市15岁以上常住居民152户428人,以记账法对居民日常蔬菜摄入量进行调查,结合蔬菜硝酸盐含量的检测结果,进行居民蔬菜硝酸盐暴露量评估。叶菜类硝酸盐含量最高(3156.94±1425.62mg/kg),茄果类的含量最低(172.36±148.08mg/kg),硝酸盐含量依次为叶菜类>根茎类>葱蒜类>瓜类>豆菜类>花菜类>茄果类,但同一类蔬菜不同品种的硝酸盐的含量差别较大;同一品种的蔬菜中硝酸盐含量差别也很大。居民每日通过蔬菜摄入的硝酸盐量为328.21mg(以中位数计),比WHO/FAO的ADI值(300mg/d)高9.4%。北京市春季蔬菜的硝酸盐污染较严重,居民仅由蔬菜摄入的硝酸盐量已经高于ADI值,因此需要加强监督管理,以保护居民健康。     

The Utilization of Ozone for Treating Vegetable Processing Lines

Adoption of ozone technologies as Food Safety treatments in the Agri-Food Industries today is still being approached with great caution. This paper reviews selected successes in using ozone UV and advanced oxidation to enhance food safety and reduce energy costs in the Agri-Food industry. Included is a preliminary case study of utilizing ozone and chlorination in a FTNON vegetable washing system. Vegetable flotation washing systems such as the FTNON equipment produced by Noord-Oost in the Netherlands have the potential to vigorously wash sand as well as floating particulate from vegetables and fruits. With minor modifications these machines can be adapted to utilize combinations of ozone, UV and chlorination. Preliminary trials indicate plate counts are lowered with the combination treatment. Future data will need to be collected to determine the levels of chlorination required to ensure residual microbial protection without detracting from product taste and quality. When developed, these systems have the potential to enhance food safety, reduce water use and wastewater discharge amounts, reduce electrical demand and increase product shelf life.     

Microbiological quality of tomatoes and peppers produced under the good agricultural practices protocol AGRO 2-1 & 2-2 in Crete, Greece

The efficiency of the good agricultural practices (GAP) protocol AGRO 2-1 & 2-2, in advancing microbiological-quality of tomatoes and peppers, was studied in greenhouses at Ierapetra, Crete, Greece. The 240 tested vegetables-samples, produced under AGRO 2-1 & 2-2, showed satisfactory quality: Listeria monocytogenes absent per 25 g; Escherichia coli < 20 Colony Forming Units per gram (CFU/g); total coliforms 4.37–4.68 log CFU/g; aerobic plate counts 5.78–5.92 log CFU/g. Based on actual results and practices evaluation, we conclude that AGRO 2-1 & 2-2 can reduce microbial hazards for consumers and furthermore can establish practices in compliance to basic Euro-Retailer-Produce GAP (EUREPGAP) requirements.