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[转帖]苯甲酸钠与维生素C可生成苯，吃维C悠着点
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苯甲酸钠与维生素C可生成苯，吃维C悠着点 近段时间，关于一些饮料中含有可致癌物质苯的说法，引起了很多市民的关注。据新华社报道，美国饮料协会已于2月底出面保证，将“使用一切手段”让所有软饮料制造商都清楚苯甲酸钠与维生素C可生成苯这一事实。英国软饮料协会也表示，将尽可能寻找合适替代品，或者不使用苯甲酸钠以降低苯含量。 记者先来到谢池巷的几家副食品店，这几家店批发兼零售，生意挺好。商家给各种饮料的销量作出了“排名”，结果显示，可口可乐和雪碧是老品牌，销量一直不错。芬达、醒目之类的果汁汽水由于颜色鲜艳，比较受孩子的喜欢；其次是一些乳酸饮料，像营养快线近来很受欢迎；而果汁饮料和茶饮料，排在第三。 记者随后在府学巷一家便利店里，将柜子上饮料的包装逐一看了个遍，几乎所有饮料都标明含有防腐剂。但消费者买饮料时，对此并未给予特别的注意。在店内，记者发现芬达、醒目、美年达橙汁等饮料摆在显著的位置。据店内的销售人员介绍，这几种果汁碳酸饮料虽然不算很畅销，但处于平均水平还是有的。 家长担心：颜色亮丽暗藏危机 “每次去超市，我的孩子专挑那些红红绿绿的饮料，我们真拿他没办法。”这是读者厉女士几天前向记者投诉时说的一句话。厉女士的儿子刚上幼儿园，每次她带儿子去商场，小孩总吵着要买那些色彩艳丽的饮料。即使不知道这些饮料是什么做的，但厉女士说光看那异样的颜色，就免不了担心饮料的安全问题。 和厉女士一样，很多家长都担心孩子喝多了有色素过多的饮料，会对身体发育带来不利影响。而市场上一些碳酸饮料，大多是用果味香料、色素调配而成，并不是天然的果汁，所以家长免不了要担心其中的质量问题。 专家解惑：漂亮饮料里究竟有什么 昨天，记者在市区各大超市买回颜色各异的“漂亮饮料”，记录其成分，并请温州市疾病预防控制中心的管鸿巧医师帮忙，揭开配料表里几种常见添加剂的“庐山真面目”。 柠檬酸：在食品中起到防腐和调味的作用，但不能过量食用。 甜蜜素，学名为“环己基氨基磺酸钠”：是一种没有营养的人工合成甜味剂，尽管它的甜度是蔗糖的30至40倍，但有研究认为，甜蜜素过量食用会对人体有害。 苯甲酸钠：是一种防腐剂，少量使用问题不大。但有研究表明，饮料中的苯甲酸钠与维生素C可发生反应，产生少量的苯。所以苯甲酸钠超量食用，对身体有害。 六偏磷酸钠：食品级六偏磷酸钠在食品工业中作为食品品质改良剂，PH值调节剂，主要用于豆类、果蔬罐头，可以稳定天然色素、保护食品色泽，用在肉类食品上可以提高持水性，防止肉中脂肪腐败，加入啤酒中能澄清酒液，防止混浊，在肉类罐头中可使脂肪乳化，保持质地均匀。 苋菜红：是一种人工合成的调色剂，国家卫生部对苋菜红的使用有严格的限制，用量不超过万分之零点五。 众所周知，苯有致癌作用， 饮料食品中大多都含有苯甲酸钠，若同时服用维C，就有可能间接苯中度，吃维C美容可得悠着点。 |
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2楼2006-03-24 16:52:23
carcinogen
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3楼2006-03-25 19:20:13
4楼2006-03-25 19:53:24
5楼2006-03-25 19:57:56
6楼2006-03-25 21:23:15
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FDA网站上关于此问题的回复。 呵呵，我觉得有些纳闷呵，如有学过化学，分析一下就会觉得苯甲酸钠与维生素C生成苯的反应速率远远不够危害到人的极别。 希望虫友们别被媒体拉着走。 Letter Regarding Benzene Levels in Soft Drinks Mr. Richard Wiles Senior Vice President Environmental Working Group 1436 U Street, NW, Suite 100 Washington, DC 20009 Dear Mr. Wiles: This is in response to your letter of February 28, 2006, to Andrew von Eschenbach, MD, Acting Commissioner of Food and Drugs, asking the Food and Drug Administration (FDA) to issue a warning to the public that soft drinks containing ascorbic acid and benzoate preservatives may contain benzene and to release the results of our tests for the presence of benzene in soft drinks. Your letter was forwarded to the Center for Food Safety and Applied Nutrition (CFSAN) for a response. In your letter, you contend that FDA has known about the presence of benzene in soft drinks since 1990, suppressed the information from the public, and asked soft drink manufacturers to voluntarily solve the problem. You describe the finding of benzene in soft drinks as a "clear health threat." You have not provided any rationale why the presence of benzene in soft drinks at low parts per billion (ppb) levels should have been considered as a clear health threat at that time or should be considered as such a threat now; both FDA and the Health Protection Branch (HPB) in Canada agreed then, as they agree now that low ppb levels of benzene found in these products did not and do not constitute an imminent health hazard. Around 1990, FDA was informed by the soft drink industry that benzene, a carcinogen, could form at the ppb level in some beverages that contained benzoate preservatives and ascorbic acid (vitamin C). After learning that benzene was present in some products, research was undertaken by both FDA and industry to understand the factors that contributed to benzene formation. We learned that elevated temperature and light can stimulate benzene formation in the presence of benzoate salts and vitamin C, while sugar and EDTA salts inhibit benzene formation. Contrary to your statement that FDA suppressed information, FDA published its findings in 1993. These findings showed both that benzene was detected only at insignificant levels and that trace levels of benzene could occasionally be detected in foods that did not contain added benzoates and vitamin C.1 Earlier, in 1992, HPB published its findings of a survey in which they sampled fruit, fruit juices, fruit drinks, and soft drinks with and without added benzoate.2 Results of HPB's survey were consistent with our findings. In November 2005, FDA received private laboratory results reporting low levels of benzene in a small number of soft drinks that contain benzoate preservatives and ascorbic acid. As follow-up to these findings, FDA began collecting and analyzing a small sample of beverages with a focus on those products that contain both benzoate and ascorbic acid. Based on currently available results from this limited survey. the vast majority of beverages sampled (including those containing both benzoate preservative and ascorbic acid) contain either no detectable benzene or levels below the 5 ppb limit for drinking water, and do not suggest a safety concern. Your letter includes a list of beverage products that were purchased in retail outlets and that contain ascorbic acid and benzoates. You cite this list as evidence that the beverage industry has not eliminated the chemical combination that can form benzene. You should know, however, that the presence of benzoates and vitamin C in a product cannot be used to conclude that elevated levels of benzene have or will form. In fact, in our current analyses, the vast majority of beverages containing both benzoate preservative and ascorbic acid contained either no detectable benzene or levels below 5 ppb. FDA is continuing to sample beverages to gain more representative data on the current situation. We intend to release our results when we have a more complete understanding of the current marketplace. Although the results to date are preliminary, they do not suggest a safety concern. Additionally, the agency has been in contact with manufacturers and industry trade associations. They have informed FDA that they are actively assessing whether their products contain benzene and will take appropriate steps to minimize benzene formation in their products, if elevated levels are found. FDA is also following up with companies whose samples of products were found to contain elevated levels of benzene in our initial survey. Once FDA has completed its beverage survey we will determine what, if any, additional action is necessary to protect the public health and to ensure that the levels of benzene in soft drinks marketed in the future are as low as possible. We appreciate your concern regarding this issue. Sincerely, Robert E. Brackett, Ph.D. Director Center for Food Safety and Applied Nutrition |
7楼2006-04-01 10:24:40