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The author:(作者)qqpublished in(发表于) 2014/6/1 10:30:44 Paragraph 1 leaves the market be detected excessive copper 98 times， can lead to kidney failure
Bamboo leaves to buy tips
Normally leaves a high temperature cooking, is dark grey and black or dark yellow, not Turquoise. If a bag of leaves, almost monochromatic green, is a bit more suspicious.
Turning green dumplings boiled smells like sulfur, bamboo incense is not obvious, leaves to cook properly after a smelling fragrance.
Not freeloaders, buy no producer name, address, date of production and the shelf life of the "three noes" bamboo leaves.
Dragon leaves the balmy seasons. Many people will buy a bamboo leaves tsungtzu, what kind of leaves the safety?
Recently, this reporter visited the bamboo leaves was found on the market sold, mainly in vacuum packaging fresh bamboo leaves and ordinary dried leaves, each package price is very cheap, only a few dollars. Vacuum packaging of fresh bamboo leaves and delicate, the color green, looks very attractive. And the packaging of dry leaves is very simple, not only dried up, the color is dark yellow. However, the reporter noted that none of these leaves packed QS certification markings.
Salespeople said vacuum fresh bamboo leaves to buy back, simple cleaning could direct tsungtzu, while the dried leaves are also soaked, cooked before using it.
On May 28, the journalists randomly from a grocer, supermarket bought 2 kinds of fresh bamboo leaves, 3 kinds of dry leaves, heavy metal contamination in natural University researchers, NGOs intervention project leader Lady using professional equipment, test the copper content in the 5 kinds of bamboo leaves. Results show that the "China" and "another spring" 2 types of vacuum packaging of fresh bamboo leaves are checking out the high content of copper.
■ 实验
1
A copper content of leaves 988PPM
The experimental objective: test wrapper leaves contain high levels of copper
Laboratory sample: sourced from supermarkets, grocer, morning of 5 kinds of bamboo leaves, there are fresh bamboo leaves and dried bamboo leaves
Test date: May 28
Experimental process: heavy metal pollution of natural University researchers, NGOs intervention project manager surnamed Zhang portable elemental analyzers to test the 5 kinds of bamboo leaves, respectively, approximately 90 seconds, the element data will appear in the Analyzer on the screen directly.
Results: align 3 packaging simple, dry leaves, copper content Analyzer does not show on the screen. Presented, which indicates that leaves "no copper", they are not checked out. Instrument at the 2 when fresh bamboo leaves, copper content on the screen number continues to climb. Ultimately, "another spring" wild bamboo leaves copper in 335PPM, while another "China brand" Reed leaves a higher copper content, about 988PPM.
Journalist view these 2 kinds of fresh bamboo leaves, packing, indicate the country of origin were from Enshi city, Hubei, is the use of traditional techniques and modern quality, technology of vacuum refining process, and main component of biologically active polysaccharides and polysaccharides containing selenium, features natural and pollution-free.
Said a woman surnamed Zhang, such as these are secondary soil in farmland, pasture, Orchard, copper should be within 50PPM, and more strict with copper content in food, bamboo leaves as a food packaging material, nor the copper content is too high. Of copper in these 2 types of bamboo leaves, but apparently "outrageous."
2
Cook remains after two fresh bamboo leaves Green
The experimental objective: validation leaves the water changes color after cooking
Laboratory sample: "China", "another spring" 2 types of copper with high content of fresh bamboo leaves, copper 1 and undetected kinds of bamboo leaves
Test date: May 29
Experimental procedure: journalist leaves 3 respectively placed in a pot, boil in water for 5 minutes, then pour the soup after cooking liquid into the bowl, see bamboo leaf colors.
Results: in accordance with the advice of experts, normally leaves at high temperature cooking, colors are usually dark yellow, yellow water, and "turning green leaves" after cooking is still green and attractive, the water turned green.
Journalists against them all and found both the dry leaves and the fresh bamboo leaves, boiled the water color changes, but leaves that contain copper, its the colour of water to stop. But previously undetected copper dry bamboo leaves, come in dark yellow in color after cooking, with a higher concentration of copper in two fresh bamboo leaves, little change in color, remain green.
Worth noting is that reporter took after high copper content of fresh bamboo leaves, could smell residue on the hands of pungent flavor.
■ 漏洞
Bamboo leaves copper standard "repeated calls are not"
Reference to food standards, experiments in a bamboo leaves over recent times
Reporters found that as early as 2008 media reported China's first dumplings was considered the national standard, which refers to "turning green leaves" phenomenon, GB proposes bamboo leaves must be pure plant shall not add anything artificial, leaves of copper ion content in the proposed maximum limits.
Reporter inquiries found yesterday, are currently no latest news, and leaves copper limits has always been "repeated calls are not" led to the current lack of specialized uniform limits.
So the actual test, the reference standard is not consistent. Reporters learned from testing organizations, most of the current reference to the tolerance limit of copper in food standard of food in the copper content ≤ 10mg/kg (1mg/kg ≈ 1PPM) apply mutatis mutandis to this limit, the testing 2 kinds of bamboo leaves, exceeding 98 times and 33 times more than doubled. There are references leaves copper content shall not exceed 50mg/kg (50PPM) the industry standard. At the international level, allegedly only in Europe set up bamboo copper leaf content of not more than 500mg/kg (equivalent to 500PPM).
Some experts pointed out that copper from leaves free to exactly how many dumplings, there is currently no relevant studies.
■ 影响
"Serious Copper toxicity can cause renal failure"
Bamboo leaves that "green" is all about then? Lion international food packaging Association General Secretary Dong Jin pointed out in an interview earlier, leaves after picking, the colors vary, most of the leaves are dark grey to black or yellow. Even fresh bamboo leaves, after a number of high-temperature steam, the color will darken, could not remain green.
But some business owners have to make zongzi and zongzi good leaf appearance, often by chemical means, when soaked bamboo leaves, add raw materials such as copper sulfate, cupric chloride, has lost its raw color leaves turn green again, so it is called "turning green leaves", may be attached to higher levels of copper. If you are using industrial-grade copper sulphate, copper chloride, copper removal, but may also be mixed with arsenic, lead, mercury and other heavy metals. Bag rice dumplings as soon as the leaves, these heavy metals are free to dumplings, if long-term or eat large amounts of, may cause copper poisoning occurred gastroenteritis, skin irritation, nausea, vomiting and other symptoms, and even lead to kidney failure.
This version of doing a Beijing News reporter Liao Ailing spared Pei
This version of photo Beijing News reporter Xue 珺 Liao Ailing
(Original title: bamboo leaves so green alert is hot)
■ 粽叶购买小贴士
●正常的粽叶经过高温蒸煮，都会呈深绿偏灰黑色或是暗黄色，不会呈青绿色。如果一袋粽叶中，几乎是一色的青绿，就比较可疑。
●返青粽煮后有硫黄味，粽香不明显，正常粽叶煮后能闻到清香。
●不要贪图便宜，购买无厂名、厂址、生产日期和保质期的“三无”粽叶产品。
又到端午粽叶飘香的季节。很多市民都会买粽叶包粽子，可什么样的粽叶才安全？
近日，记者走访发现市场上售卖的粽叶，主要有真空包装的鲜粽叶和普通干粽叶，每包价格都很便宜，只有几元钱。而真空鲜粽叶的包装更精致一些，颜色碧绿，看上去很诱人。而干粽叶的包装则很简易，不仅干枯，颜色也偏暗黄。不过，记者注意到，这些粽叶包装都没有QS认证标识。
销售人员称，真空鲜粽叶买回去后，简单清洗就能直接包粽子，而干粽叶则还要将其浸泡、蒸煮后才能使用。
5月28日，记者随机从菜市场、超市等地购买了2种鲜粽叶、3种干粽叶，请民间环保组织自然大学研究员、重金属污染干预项目负责人张女士使用专业仪器，测试这5种粽叶中的铜含量。结果显示，“华鹤”和“又一春”这2种真空包装的鲜粽叶都检出了含量颇高的铜。
一款粽叶铜含量达988PPM
实验目的：测试包装粽叶是否含有高含量的铜
实验样品：采购自超市、菜市场、早市的5种粽叶，有鲜粽叶也有干粽叶
实验时间：5月28日
实验过程：民间环保组织自然大学研究员、重金属污染干预项目负责人张女士，使用便携式元素分析仪对5种粽叶分别进行测试，大约90秒钟，元素数据就会直接显示在分析仪的屏幕中。
实验结果：对准3种包装简易的干粽叶，分析仪屏幕上并没显示出铜含量。张女士介绍，这表示这些粽叶里“不含铜”，所以未检出。而仪器对准2种鲜粽叶时，屏幕上铜含量数值不断攀升。最终，“又一春”野生粽叶铜含量为335PPM，而另一种“华鹤”牌箬叶铜含量更高，约988PPM。
记者查看这2种鲜粽叶外包装，标明原产地都来自湖北恩施，都称是采用传统工艺和现代保质、真空保鲜技术精制加工而成，主要成分为生理活性多糖和硒多糖，特点天然无污染等。
张女士说，诸如农田、牧场、果园这些属于二级土壤的，铜含量应在50PPM内，而食品中对铜含量要求更严，粽叶作为食品包装材料，也不能铜含量太高。而这2种粽叶中的铜，却很明显“高得吓人”。
两种鲜粽叶煮后依然很绿
实验目的：验证粽叶水煮后的颜色变化
实验样品：“华鹤”“又一春”2种铜含量高的鲜粽叶，以及未检出铜的1种干粽叶
实验时间：5月29日
实验过程：记者把3种粽叶分别放到锅中，在水中煮沸5分钟，然后把煮后的汤液倒入碗中，查看粽叶颜色。
实验结果：按照多位专家的支招，正常粽叶经高温蒸煮，颜色一般会发暗发黄，水偏黄色，而“返青粽叶”煮后则仍然青绿诱人，水变绿。
记者一一对照，发现无论是干粽叶还是鲜粽叶，煮后的水颜色都有变化，不过含有铜的粽叶，其水的颜色要更深一些。但此前未检出铜的干粽叶，在煮后颜色变得更暗黄了一些，而有高含量铜的两种鲜粽叶，颜色变化不大，依然保持青绿。
值得注意的是，记者拿过铜含量高的鲜粽叶后，手上能闻到一股残留的刺鼻味。
粽叶铜标准“千呼万唤未出来”
参照食品标准，实验中一款粽叶超标近百倍
记者发现，早在2008年媒体就报道称我国正酝酿出台首部粽子国家标准，其中提到针对“返青粽叶”现象，国标拟规定粽叶必须是纯植物，不得人工添加任何东西，对粽叶的铜离子含量拟设最高限量。
但昨天记者查询发现，目前暂无最新消息，粽叶铜限量标准始终“千呼万唤未出来”，导致目前缺乏专门统一的限量标准。
因此实际测试中，参照的标准并不一致。记者从一些检测机构了解到，目前多数都参照的《食品中铜含量限量卫生标准》中食品铜含量≤10mg/kg(1mg/kg≈1PPM)，比照这个限量，此次测试的2种粽叶，超标33倍和98倍多。也有地方提到粽叶含铜量不得超50mg/kg(相当于50PPM)的行业标准。在国际上，据称只有欧洲设定了粽叶铜含量为不超过500mg/kg(相当于500PPM)。
也有专家指出，粽叶中的铜究竟会有多少游离到粽子中，目前尚无相关研究。
“严重铜中毒可引发肾衰竭”
粽叶那么“鲜绿”是怎么回事呢？国际食品包装协会秘书长董金狮此前接受采访时指出，粽叶采摘后，颜色肯定会发生变化，大多数粽叶会呈深绿偏灰黑色或黄色。即使是新鲜粽叶，多次高温蒸煮后，颜色也会变暗，不可能一直保持鲜绿。
但一些商家为了让粽子和粽叶卖相好，往往会采取化学手段，在浸泡粽叶时，加入硫酸铜、氯化铜等原料，让已失去原色泽的粽叶重新变绿，因此被称为“返青粽叶”，可能会附着含量较高的铜。如果使用的是工业级的硫酸铜、氯化铜，除铜外，还可能夹杂砷、铅、汞等重金属。包粽子一旦用了这样的粽叶，这些重金属会游离到粽子，人如果长期或大量食用，可能引起铜中毒，出现肠胃炎，皮肤红肿、恶心呕吐等症状，甚至导致肾脏功能衰竭。
本版采写 新京报记者 廖爱玲 饶沛
本版摄影 新京报记者 薛珺 廖爱玲
(原标题：粽叶太鲜绿警惕被泡过)
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