Thursday, November 1, 2012
Wednesday, October 24, 2012
Sunday, September 23, 2012
Wednesday, September 19, 2012
Sunday, September 16, 2012
Sunday, September 2, 2012
Saturday, September 1, 2012
Monday, August 20, 2012
Sunday, August 19, 2012
Thursday, August 9, 2012
Golden Slice Bird's Nest Dessert 黄金燕窝糖水
材料有燕窝,泡参,白果,冰糖和金箔。
Ingredients: Bird's Nest, Ginseng Slices, Ginko Nuts, Rock Sugar, Thin Edible Gold slices
Saturday, August 4, 2012
Saturday, July 21, 2012
Thursday, July 19, 2012
Swiftlet's Cafe
基于现今社会热烈提倡野生动物保护法以支持环保活动,我个人建议将鱼翅除出宴客菜单而采用燕窝食品代替。
The topic of conservation and animal protection has dominated the headlines in recent years. I am of the personal belief that Shark's Fin should be excluded from Chinese dinner menus and banquets. Bird's Nest can then be used as a replacement, considering its value and prestige.
以下是几种燕窝烹调法供各位参考:
Here are some Bird's Nest recipes for your reading pleasure.
Main Ingredients: Bird's Nest 60g, Coconut Milk 50ml, Japanese Pumpkin (1 x 350g)
Supplementary Ingredients: Haw Flakes 10g
Seasoning / Condiments: Rock Sugar, Honey, Ginger (approximate)
Method:
1. Cut off the top of pumpkin (1/5 of height of pumpkin), remove seeds
2. Place bird's nest into pumpkin, together with coconut milk, haw flakes, rock sugar. Fill up pumpkin with water.
3. Steam pumpkin with cap for 30 minutes and dish is ready to serve.
Main Ingredients: Bird's Nest 10g, White Fungus 15g, Cordyceps 3 sticks, Red Dates x 3, Lotus Seeds 20g
Seasoning / Condiments: Salt (approximate)
Method:
1. Soak Bird's Nest for 4 - 8 hours, remove impurities.
2. Soak Cordyceps, red dates separately in warm water for 10 minutes.
3. Place bird's nest, cordyceps, red dates, white fungus, lotus seeds into slow cooker, add in 6 bowls of water, simmer in medium heat for 15 minutes.
4. Add in suitable amount of salt and dish is ready to serve.
Main Ingredients: Papaya x 1, Fritillary Bulbus x 6, cleaned Bird's Nest 25 g, Milk 70ml
Seasoning: Condiments: Honey, Rock Sugar (approximate)
Method:
1. Clean Papaya, cut it into half, remove seeds, forming a bowl.
2. Pre-soak and steam Fritillary Bulbus for 8 minutes
3. Add in milk, Fritillary Bulbus, bird's nest. honey, rock sugar into papaya.
4. Steam papaya with cap on for 10 - 15 minutes and dish is ready to serve.
The topic of conservation and animal protection has dominated the headlines in recent years. I am of the personal belief that Shark's Fin should be excluded from Chinese dinner menus and banquets. Bird's Nest can then be used as a replacement, considering its value and prestige.
以下是几种燕窝烹调法供各位参考:
Here are some Bird's Nest recipes for your reading pleasure.
主料: 水发官燕60克,椰汁50克,日本金瓜1个(约350克)
配料: 山楂片10克
调料: 冰糖水、蜂蜜、姜汁各适量
Main Ingredients: Bird's Nest 60g, Coconut Milk 50ml, Japanese Pumpkin (1 x 350g)
Supplementary Ingredients: Haw Flakes 10g
Seasoning / Condiments: Rock Sugar, Honey, Ginger (approximate)
制法:
1. 金瓜从顶部1/5处横切为二,挖去瓤。
2. 金瓜内放燕窝、椰汁、山楂片、冰糖水,隔水炖30分钟即可。
Method:
1. Cut off the top of pumpkin (1/5 of height of pumpkin), remove seeds
2. Place bird's nest into pumpkin, together with coconut milk, haw flakes, rock sugar. Fill up pumpkin with water.
3. Steam pumpkin with cap for 30 minutes and dish is ready to serve.
主料: 官燕10克,银耳15克,冬虫草3根,红枣3枚,百合20克
调料: 盐适量
Main Ingredients: Bird's Nest 10g, White Fungus 15g, Cordyceps 3 sticks, Red Dates x 3, Lotus Seeds 20g
Seasoning / Condiments: Salt (approximate)
制法:
1. 将官燕放入净水中浸泡4~8小时,挑去杂质。
2. 将冬虫草、红枣分别用温水浸泡10分钟。
3. 将官燕、冬虫草、红枣、银耳、百合放入炖盅内,加六碗水,用中火隔水炖15分钟,放入适量盐调味即可。
Method:
1. Soak Bird's Nest for 4 - 8 hours, remove impurities.
2. Soak Cordyceps, red dates separately in warm water for 10 minutes.
3. Place bird's nest, cordyceps, red dates, white fungus, lotus seeds into slow cooker, add in 6 bowls of water, simmer in medium heat for 15 minutes.
4. Add in suitable amount of salt and dish is ready to serve.
主料: 木瓜1个,川贝6粒,发制好的官燕25克,鲜奶70克
调料: 蜂蜜、冰糖各适量
Main Ingredients: Papaya x 1, Fritillary Bulbus x 6, cleaned Bird's Nest 25 g, Milk 70ml
Seasoning: Condiments: Honey, Rock Sugar (approximate)
制法:
1. 将木瓜洗净,一切为二,挖去瓤。
2. 木瓜中加鲜奶、川贝(提前浸泡,再蒸至八分软)、官燕, 蜂蜜、冰糖,盖上木瓜盖,隔水炖10~15分钟即可。
Method:
1. Clean Papaya, cut it into half, remove seeds, forming a bowl.
2. Pre-soak and steam Fritillary Bulbus for 8 minutes
3. Add in milk, Fritillary Bulbus, bird's nest. honey, rock sugar into papaya.
4. Steam papaya with cap on for 10 - 15 minutes and dish is ready to serve.
图片资料摘自青岛出版社"吃燕窝"
Sunday, July 8, 2012
Tuesday, July 3, 2012
Sunday, June 24, 2012
Sunday, June 10, 2012
Sunday, June 3, 2012
Sunday, May 27, 2012
Thursday, May 24, 2012
BIRD'S NEST EXPORT . 燕窝出口。
燕窝因种种因素,被禁出口到中国近半年多。造成国内与燕窝相关行业都大受影响,燕窝价格也滑落不少,令大家不知所措。有些业者干脆不把采好的燕窝卖掉,也有一些燕屋主,暂时不采燕窝,以便让小燕子继续在燕屋成长,这也是一种很好的策略。不过,对于一些在这近几个月前开声的新燕屋经营者,开始引燕时,会比较费力。总得来说,对于这一次燕窝价格的强烈波动,相信大家也很难受。
For a variety of factors, Bird's Nest has been rejected entry as an export to China for half a year now. This is caused several knock-down effects on the bird nest trade in Malaysia. The price of bird best has also plummeted due to over supply, resulting in problems for the traders. Some suppliers have taken to holding on to stock. Swiftlet House owners have also stopped harvesting nests, to allow the swiftlets to continue living in the nests, this is also a good strategy. However, this will give new home owners some problems when it comes to attracting swiftlets. All in all, this current predicament has left several related business owners up in arms.
Saturday, May 19, 2012
(中國‧北京15日訊)農業及農基工業部長拿督斯里諾奧馬今日與中國國家質量監督檢驗檢疫總局局長支樹平會面後取得積極的成果,雙方預料可在兩週內解決燕窩出口的技術問題,並儘速簽署出口協定。
他說,關於亞硝酸鹽限量在30ppm的問題已克服,目前僅剩下一些技術問題,他相信一旦技術問題解決和經內閣核准後,預料大馬燕窩很快就能重新出口中國。
諾奧馬是今日率領農業部高級官員與中國質量監督檢驗檢疫總局局長支樹平進行會談後,向隨團的大馬記者發表談話。
他說,獸醫局總監拿督阿都阿茲將會留在北京處理燕窩出口協定事宜,包括鑑定出口商的名單和燕屋的詳情等,一直到問題妥善解決為止。
庫存200公噸燕窩
據阿都阿茲說,大馬目前庫存了200公噸的燕窩,而中國每年的燕窩需求高達500至600公噸。
諾奧馬也向中方保證大馬將會符合所有的條件,大馬也同意出口協定草案中所有的條件,只是等待協定的簽署而已。
“我有信心技術問題可在本週內解決,可能快至明天就獲得解決,緊接著就可進入下一步驟。”
大馬的燕窩業的價值超過10億令吉,而凍結出口前的價值是介於1億2千萬至1億5千萬令吉,凍結後下跌至5千萬令吉。
出口禁令影響業者
諾奧馬說,由於燕窩業是一項高效應計劃,而且更是他的關鍵績效指標,也是經濟轉型執行方案下的啟動計劃,因此,該部積極處理此事。
他也說,燕窩出口禁令也對引燕業者構成影響,單是農業銀行的貸款就高達1億令吉,問題若一再拖延,將會令到養燕業崩潰,投資者也會因為中國的禁令,導致大馬的燕窩價格下跌50%的情況下,而無法償還貸款。
隨著首相拿督斯里納吉和中國總理溫家寶於4月1日在南寧同意讓大馬燕窩重新進入中國市場達致共識後,農長是在首相指示下,前來中國商討加速解決出口協定問題。
針對大馬要求在協定簽署前過度期間能夠有條件出口燕窩到中國的問題,農長說,由於中方相信問題很快能解決,因此,就等待協定的簽署。
他欣慰雙方今日達致良好的會談成果,同時更進一步加強雙邊關係。
強制燕屋進行登記
違例者不能出口
違例者不能出口
諾奧馬也說,國內所有的燕屋強制性規定向農業部進行登記,否則不能出口。
他遺憾由於燕屋業者拒絕登記,導致他的關鍵績效指標呈紅色,即未達標。
他說,去年只有30%的燕屋業者進行登記。
他說,迄今已有8家公司獲准出口燕窩到中國,他重申政府並沒有設定限額和壟斷,只要符合三大條件就能獲得牧場作業規範證書,就能出口燕窩。
據阿都阿茲說,只有依據指南在衛生和控制噪音及不被人投訴的燕屋才會獲頒證書。
他說,還有超過20家待審核,當局還開放申請,申請者也必須獲得獸醫局的獸醫衛生認證(VHM)、衛生局認證及大馬多媒体委員會的“無線射頻識別系統(RFID)”證書。
針對申請程序緩慢問題,農長重申,大馬著重燕窩素質,並根據出口協定的條件來審核,大馬不希望燕窩業再發生事故,因為要復甦非常艱難。
他也說,政府也會設立了一套產品追踪体系,以追踪和鑑別產品產地,保障燕窩的安全,避免大馬成為燕窩的轉站點
Sunday, April 29, 2012
Sunday, April 22, 2012
Saturday, April 7, 2012
Thursday, April 5, 2012
Thursday, March 29, 2012
Saturday, March 17, 2012
NEW NEST. 新燕窝
3月份,燕子正在孵蛋。一般上,燕窝太久了,干了,燕子们也会把它给淘汰。天然界本来就潜在着一股美丽无比的力量,维护了大自然的定律,整体来说燕窝是可以用的。某些人出錯了,還帶壞了市場也帶壞了國家名聲,大家都受到這一次燕窩風暴的打擊,對燕窩的市場以及出口的心思都給搞垮了,還能坐以待斃嗎? 希明天會更好,也希望大家能寄一些以美麗可愛燕窩有關的相片及種種,讓大家分享。 一 jblim 2012-03-17.
It is March and the swiftlets are incubating the eggs. In most cases, once the swiftlet nests have reached a certain age, they will dry up and become abandoned by the swiftlets. Nature is indeed a huge mystical force, which protects its rhythm and flow.
In general, these swiftlet nests are usable. A few merchants may have made mistakes, resulting in the affecting of a county's reputation in swiftlet dealings. No one is spared the impact of this swiftlet saga, from the swiftlet nest market to its export potential, everything has been dealt a blow. Should we just wait and allow the situation to improve itself? Here's to a better tomorrow, and hoping that everyone can send in some of your beautiful swiftlet pictures, display your love for the swiftlets, share it with everyone else.
Friday, March 16, 2012
Monday, March 5, 2012
Thursday, March 1, 2012
Wednesday, February 29, 2012
北京2月28日讯
燕窝及动物源性中药材等禁携入境
2012年02月29日 06:49
来源:法制日报
字号:T|T
0人参与0 0条评论0 打印 转发
本报记者韩乐悟
记者今天从国家质检总局获悉,为防止动植物疫病及有害生物传入,保护我国农林牧渔业生产和公共卫生安全,农业部、国家质检总局近日联合修订发布了《中华人民共和国禁止携带、邮寄进境的动植物及其产品名录》。新名录明确将燕窝、动物源性中药材、转基因生物材料等列为禁止携带、邮寄进境的物品。包括生鲜奶、酸奶、奶油、奶酪等在内的动物源性奶及奶制品也被禁止。新名录自发布之日起生效。
国家质检总局办公厅主任、新闻发言人李元平在今天召开的新闻发布会上介绍说,新名录与1992年版原名录相比,突出了三大变化:一是对过去分别发布实施的动物和植物两份禁止进境物名录进行合并,明确适用对象为“旅客携带、邮寄进境的动植物及其产品”;二是对活动物、肉类、奶制品、动物源性饲料、蔬菜等物品的限制范围更清晰、更细化;三是明确将燕窝、动物源性中药材、动物源性肥料、有机栽培介质、转基因生物材料列为禁止携带、邮寄进境的物品。
在农业部官方网站上,记者见到今天以农业部、国家质检总局联合公告形式推出的新名录,共包括禁止携带、邮寄进境的动植物及其产品和其他检疫物类三大类16个细名录。其中动物及动物产品类包括除犬、猫之外的活动物,生熟肉类及其制品,蛋及其制品,动物源性饲料、中药材、肥料等;植物及植物产品类包括新鲜水果、蔬菜,烟叶(不含烟丝),种子(苗)、苗木及其他具有繁殖能力的植物材料,有机栽培介质,土壤等;其他检疫物类包括动物标本,菌种、毒种,细胞、器官组织、血液及其制品等生物材料,转基因生物材料等。
公告注明两点:其一,通过携带或邮寄方式进境的动植物及其产品和其他检疫物,经过国家有关行政管理部门审批许可,并具有输出国或地区官方出具的检疫证书,不受此名录的限制。其二,具有输出国官方兽医出具的动物检疫证书和疫苗接种证书的犬、猫等宠物,每人仅限一只。
据国家质检总局提供的数字,2011年全国出入境检验检疫机构共检验检疫进出境动植物及其产品196.5万批、1556.2亿美元,截获各类动物疫病和植物有害生物3972种、50.02万次,同比分别增长8.35%和24.5%,其中截获禁止进境旅客携带物、邮寄物30.7万批次,增长10.54%。2012年1月,在进境农产品检疫过程中共截获有害生物1350种27475次,其中检疫性有害生物86种2128次,一般有害生物1264种25347次。
近年相关数字、信息无不在说明,随着经济发展、贸易往来增多、人员出入境频繁等,出入境生物安全风险不断加大。
质检总局提醒社会各界遵守规定,积极配合新名录的实施,确保进出境生物安全。
本报北京2月28日讯
Nitrite 亚硝酸盐
Nitrite
From Wikipedia, the free encyclopedia
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This article may require copy editing for grammar, style, cohesion, tone, or spelling. You can assist by editing it. (September 2011)
Nitrite ion with an O-N-O bond angle of ca. 120°
Space-filling model of the nitrite ion
The nitrite ion has the chemical formula NO2−. The anion is symmetric with equal N-O bond lengths and a O-N-O bond angle of ca. 120°. On protonation the unstable weak acid nitrous acid is produced. Nitrite can be oxidised or reduced, with product somewhat dependent on the oxidizing/reducing agent. The nitrite ion is an ambidentate ligand and is known to bond to metal centres in at least five different ways.[1] Nitrite is important in biochemistry as a source of the vasodilator nitric oxide. Nitrites are used for curing meat. In organic chemistry the NO2 group is present in nitrous acid esters and nitro compounds.
Contents
[hide]
• 1 The nitrite ion
o 1.1 Nitrite salts
o 1.2 Structure
o 1.3 Acid-base properties
o 1.4 Oxidation and reduction
o 1.5 Coordination complexes
o 1.6 Nitrite in biochemistry
• 2 Organic nitrites and nitro compounds
• 3 See also
• 4 References
• 5 External links
• 6 Bibliography
[edit] The nitrite ion
[edit] Nitrite salts
Sodium nitrite is made industrially by passing nitrous fumes into aqueous sodium hydroxide or sodium carbonate solution.[1]
NO + NO2 + 2NaOH (or Na2CO3) → 2NaNO2 +H2O ( or CO2)
The product is purified by recrystallization. Alkali metal nitrites are thermally stable up to and beyond the melting point (441 °C for KNO2). Ammonium nitrite can be made from dinitrogen trioxide, N2O3, which is formally the anhydride of nitrous acid.
2NH3 + H2O +N2O3 → 2NH4NO2
This compound may decompose explosively on heating.
In organic chemistry nitrites are used in diazotization reactions.
[edit] Structure
The two canonical structures of NO2−, which contribute to the resonance hybrid for the nitrite ion
The nitrite ion has a symmetrical structure (C2v symmetry) with both N-O bonds having equal length. In valence bond theory it is described as a resonance hybrid with equal contributions from two canonical forms that are mirror images of each other. In molecular orbital theory there is a sigma bond between each oxygen atom and the nitrogen atom, and a delocalized pi bond made from the p orbitals on nitrogen and oxygen atoms which are perpendicular to the plane of the molecule. The negative charge of the ion is equally distributed on the two oxygen atoms. Both nitrogen and oxygen atoms carry a lone pair of electrons. Therefore the nitrite ion is a Lewis base. Moreover, it can act as an ambidentate ligand towards a metal ion, donating a pair of electrons from either nitrogen or oxygen atoms.
[edit] Acid-base properties
Dimensions of trans HONO (from the microwave spectrum)
In aqueous solution nitrous acid is a weak acid.
HNO2 H+ + NO2-; pKa = ca. 3.3 at 18 °C[2]
Nitrous acid is volatile; in the gas phase it exists predominantly as a trans- planar molecule. In solution it is unstable with respect to the disproportionation reaction
3HNO2 (aq) H3O+ + NO3- + 2NO
This reaction is slow at 0 °C.[1] Addition of acid to a solution of a nitrite in the presence of a reducing agent such as iron(II) is a way to make nitric oxide, NO, in the laboratory.
[edit] Oxidation and reduction
The formal oxidation state of the nitrogen atom in a nitrite is +3. This means that it is can be either oxidised to oxidation states +4 and +5 or reduced to oxidation states as low as -3. Standard reduction potentials for reactions directly involving nitrous acid are shown in the table.[3]
Half-reaction E0/V
NO3- + 3H+ + 2e- HNO2 + H2O +0.94
2HNO2+ 4H+ + 4e- H2N2O2 + 2H2O +0.86
N2O4 + 2H+ + 2e- 2HNO2 +1.065
2HNO2+ 4H+ + 4e- N2O + 3H2O +1.29
The data can be extended to include products in lower oxidation states. For example,
H2N2O2 + 2H+ + 2e- N2 + 2H2O; E0 = 2.65V
Oxidation reactions usually result in the formation of the nitrate ion, with nitrogen in oxidation state +5. For example, oxidation with permanganate can be used for quantitative analysis of nitrite, by titration.
5NO2- + 2MnO4- + 6H+ → 5NO3- + 2Mn2+ + 3H2O
The product of reduction reactions are various depending on the reducing agent used. With sulfur dioxide the products are NO and N2O; with tin(II), Sn2+, the product is hyponitrous acid, H2N2O2; reduction all the way to ammonia occurs with hydrogen sulfide. With the hydrazinium cation, N2H5+, hydrogen azide, HN3, is produced
HNO2 + N2H5+ → HN3 + H2O + H3O+
which can also further react with nitrite
HNO2 + HN3 → N2O + N2 + H2O
This reaction is unusual in that it involves compounds with nitrogen in four different oxidation states.[1]
[edit] Coordination complexes
The nitrite ion is known to form complexes in at least five different ways.[1]
1. When donation is from nitrogen to a metal centre, the complex is known as a nitro- complex.
2. When donation is from one oxygen to a metal centre, the complex is known as a nitrito- complex.
3. Both oxygen atom may donate to a metal centre, forming a chelate complex.
4. A nitrite ion can form an unsymmetrical bridge between two metal centres, donating through nitrogen to one metal and oxygen to the other.
5. A single oxygen atom can bridge to two metal centres.
Alfred Werner studied the nitro-nitrito isomerism (1 and 2) extensively. The red isomer of cobalt pentammine with nitrite is now known to be a nitrito complex, [Co(NH3)5(ONO)]2+; it is metastable and isomerizes to the yellow, nitro complex [Co(NH3)5(NO2)]2+. An example of chelating nitrite (3) was found in [Cu(bipy)2(O2N)]NO3; bipy is the bidentate ligand 2,2'bypyridyl and the two bipy ligands occupy four coordination sites on the copper ion so the nitrite is forced to occupy two sites in order to achieve an octahedral environment around the copper ion. Examples of 4 and 5 are illustrated.[1]
[edit] Nitrite in biochemistry
Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, in a reaction with the meat's myoglobin, gives the product a desirable dark red color. Because of the toxicity of nitrite (the lethal dose of nitrite for humans is about 22 mg per kg body weight), the maximum allowed nitrite concentration in meat products is 200 ppm. Under certain conditions, especially during cooking, nitrites in meat can react with degradation products of amino acids, forming nitrosamines, which are known carcinogens.[4]
Nitrite is detected and analyzed by the Griess Reaction, involving the formation of a deep red-colored azo dye upon treatment of a NO2−-containing sample with sulfanilic acid and naphthyl-1-amine in the presence of acid.[5] Nitrite can be reduced to nitric oxide or ammonia by many species of bacteria. Under hypoxic conditions, nitrite may release nitric oxide, which causes potent vasodilation. Several mechanisms for nitrite conversion to NO have been described including enzymatic reduction by xanthine oxidoreductase, nitrite reductase and NO synthase (NOS), as well as nonenzymatic acidic disproportionation.
Processed meat like sausages or leverpostej that contains nitrite increase the risk for pancreatic cancer with 20% for every 50 gram ingested per day. Five sausages equals doubled cancer risk.[6][7]
[edit] Organic nitrites and nitro compounds
A nitrite ester
aromatic nitration
In organic chemistry, nitrites are esters of nitrous acid and contain the nitrosooxy functional group. Nitro compounds contain the C-NO2 group. Nitrites have the general formula RONO, where R is an aryl or alkyl group. Amyl nitrite is used in medicine for the treatment of heart diseases. A classic named reaction for the synthesis of alkyl nitrites is the Meyer synthesis[8][9] in which alkyl halides react with metallic nitrites to a mixture to nitroalkanes and nitrites.
Nitrobenzene is a simple example of a nitro compound. In aromatic nitration reaction a C-H bond is broken leaving the two electron on the carbon atom. The two electrons are added to the nitronium ion reducing it to nitrite.
[edit] See also
• Curing (food preservation)
[edit] References
1. ^ a b c d e f Greenwood, pp 461-464
2. ^ IUPAC SC-Database A comprehensive database of published data on equilibrium constants of metal complexes and ligands
3. ^ Greenwood, p 431
4. ^ Jakszyn P, Gonzalez CA. Nitrosamine and related food intake and gastric and oesophageal cancer risk: a systematic review of the epidemiological evidence. World J Gastroenterol. 2006 Jul 21;12(27):4296-303. PubMed
5. ^ V. M. Ivanov (2004). "The 125th Anniversary of the Griess Reagent". Journal of Analytical Chemistry 59 (10): 1002–1005. doi:10.1023/B:JANC.0000043920.77446.d7. Translated from V. M. Ivanov (2004). Zhurnal Analiticheskoi Khimii 59 (10): 1109–1112.
6. ^ bbc.co.uk - Processed meat 'linked to pancreatic cancer', 2012-01-13
7. ^ mendeley.com - Meat Consumption and Cancer Risk, PLoS Medicine (2007) Volume: 4, Issue: 12, Publisher: Public Library of Science, Pages: 4, DOI: 10.1371/journal.pmed.0040345, PubMed: 18076281
8. ^ Victor Meyer (1872). "Ueber die Nitroverbindungen der Fettreihe". Justus Liebig's Annalen der Chemie 171 (1): 1–56. doi:10.1002/jlac.18741710102.; Victor Meyer, J. Locher (1876). "Ueber die Pseudonitrole, die Isomeren der Nitrolsäuren". Justus Liebig's Annalen der Chemie 180 (1–2): 133–155. doi:10.1002/jlac.18761800113.; V. Meyer and Stüber (1872). "Vorläufige Mittheilung". Chemische Berichte 5: 203–205. doi:10.1002/cber.18720050165.; Victor Meyer, O. Stüber (1872). "Ueber die Nitroverbindungen der Fettreihe". Chemische Berichte 5: 399. doi:10.1002/cber.187200501121.; Victor Meyer, A. Rilliet (1872). "Ueber die Nitroverbindungen der Fettreiche. Dritte Mittheilung". Chemische Berichte 5 (2): 1029–1034. doi:10.1002/cber.187200502133.; Victor Meyer, C. Chojnacki (1872). "Ueber die Nitroverbindungen der Fettreihe. Vierte Mittheilung". Chemische Berichte 5 (2): 1034–1038. doi:10.1002/cber.187200502134.
9. ^ Robert B. Reynolds, Homer Adkins (1929). "The Relationship of the Constitution of Certain Alky Halides to the Formation of Nitroparaffins and Alkyl Nitrites". Journal of the American Chemical Society 51 (1): 279–287. doi:10.1021/ja01376a037.
[edit] External links
• Material Safety Data Sheet, sodium nitrite
• ATSDR - Case Studies in Environmental Medicine - Nitrate/Nitrite Toxicity U.S. Department of Health and Human Services (public domain)
[edit] Bibliography
亚硝酸盐Nitrite
1. 亚硝酸盐_百度百科
baike.baidu.com/view/151075.htm - Translate this page
亚硝酸盐,一类无机化合物的总称。主要指亚硝酸钠,亚硝酸钠为白色至淡黄色粉末或颗粒状,味微咸,易溶于水。外观及滋味都与食盐相似,并在工业、建筑业中广为 ...
亚硝酸盐,一类无机化合物的总称。主要指亚硝酸钠,亚硝酸钠为白色至淡黄色粉末或颗粒状,味微咸,易溶于水。外观及滋味都与食盐相似,并在工业、建筑业中广为使用,肉类制品中也允许作为发色剂限量使用。由亚硝酸盐引起食物中毒的机率较高。食入0.3~0.5克的亚硝酸盐即可引起中毒甚至死亡。
目录
简介
最新相关报道
制法
毒性
毒性概述
急性中毒原因
慢性中毒(包括癌变)原因
亚硝酸盐中毒症状
如何通过变性血红蛋白试验检测亚硝酸盐中毒
亚硝酸盐中毒的抢救
亚硝酸盐的含量测定
测定准备
操作方法
尿检
介绍
临床意义
预防措施
亚硝酸盐来源
亚硝酸盐食用过多处理方法
如何减少亚硝酸盐和亚硝基化合物的摄入
简介
最新相关报道
制法
毒性
毒性概述
急性中毒原因
慢性中毒(包括癌变)原因
亚硝酸盐中毒症状
如何通过变性血红蛋白试验检测亚硝酸盐中毒
亚硝酸盐中毒的抢救
亚硝酸盐的含量测定
测定准备
操作方法
尿检
介绍
临床意义
预防措施
亚硝酸盐来源
亚硝酸盐食用过多处理方法
如何减少亚硝酸盐和亚硝基化合物的摄入
展开
编辑本段简介
Nitrite(缩写:NIT)
亚硝酸盐,亚硝酸盐类食物中毒又称肠原性青紫病、紫绀症、乌嘴病,是一种白色不透明结晶的化工产品,形状极似食盐。工业盐(又称私盐)因系由化工原料加工制成,含有大量的亚硝酸盐。为白色至淡黄色粉末或颗粒状,味微咸,易溶于水。外观及滋味都与食盐相似,并在工业、建筑业中广为使用,肉类制品中也允许作为发色剂限量使用。由亚硝酸盐引起食物中毒的机率较高。食入0.3~0.5克的亚硝酸盐即可引起中毒,约3克可致死。
亚硝酸盐中毒是指由于食用硝酸盐或亚硝酸盐含量较高的腌制肉制品、泡菜及变质的蔬菜可引起中毒,
亚硝酸盐
或者误将工业用亚硝酸钠作为食盐食用而引起,也可见于饮用含有硝酸盐或亚硝酸盐苦井水、蒸锅水后,亚硝酸盐能使血液中正常携氧的低铁血红蛋白氧化成高铁血红蛋白,因而失去携氧能力而引起组织缺氧。亚硝酸盐是剧毒物质,成人摄入0.2一0.5克即可引起中毒,3克即可致死。
硝酸盐
亚硝酸盐同时还是一种致癌物质,据研究,食道癌与患者摄入的亚硝酸盐量呈正相关性,亚硝酸盐的致瘤机理是:在胃酸等环境下亚硝酸盐与食物中的仲胺、叔胺和酰胺等反应生成强致癌物N一亚硝胺。亚硝胺还能够透过胎盘进入胎儿体内,对胎儿有致崎作用。6个月以内的婴儿对亚硝酸盐特别敏感,临床上患“高铁血红蛋白症”的婴儿即是食用亚硝酸盐或硝酸盐浓度高的食品引起的,症状为缺氧,出现紫绀,甚至死亡,因此欧盟规定亚硝酸盐严禁用于婴儿食品。亚硝酸盐中毒发病急速,一般潜伏期1一3小时,中毒的主要特点是由于组织缺氧引起的紫绀现象,如口唇、舌尖、指尖青紫,重者眼结膜、面部及全身皮肤青紫。头晕、头疼、乏力、心跳加速嗜睡或烦躁、呼吸困难、恶心、呕吐、腹痛、腹泻,严重者昏迷、惊厥、大小便失禁,可因呼吸衰竭而死亡[1]。
作为防腐剂而应用在肉质食品里的亚硝酸盐一直被认为是致癌物,但是美国国家卫生研究院的科学家近日却发现,这种致癌物能制作成药物,用来治疗镰状细胞血症和心脏病等多种疾病,这一发现令人瞠目结舌。
100年来,科学家认为亚硝酸盐没有任何益处,但是今天,科学家却发现了它的价值所在。据美国全波广播公司9月5日报道,在研究一种与亚硝酸盐相关的化合物——氧化一氮时,马克T格拉德温博士和心脏病专家理查德-坎农博士意外发现了亚硝酸盐的药用价值。氧化一氮可以扩张血管,进而增加血液流量,但无法用作药物。不过,经常被用作食品防腐剂的亚硝酸盐却有着和氧化一氮相似的功效,而且可以入药,所以两位科学家想到了亚硝酸盐。
随后,科学家进行了临床试验。他们给健康的志愿者注入微量亚硝酸盐,结果志愿者体内血液流量增加了两倍,而当志愿者运动时,体内的亚硝酸盐含量马上直线下降,说明身体正在积极使用亚硝酸盐。所以,科学家认为,亚硝酸盐可以用作药物,用来治疗镰状细胞血症、心脏病、脑动脉瘤等和血液流量有关的疾病。
对此,格拉德温博士戏称说,“我们等于把人体器官当成了热狗[2],加入亚硝酸盐就相当于加入了保护措施,保卫心脏、肺和大脑缺氧时,细胞不会因为缺少氧气而死亡。”
编辑本段最新相关报道
8月15日,浙江省工商局网站发布信息称,在针对流通领域的食品质量抽检中,发现血燕产品普遍存在亚硝酸盐含量严重超标问题,问题血燕主要来自马来西亚。动辄上万元一两的血燕,被爆出是经染色制成的,而且部分血燕有害物质亚硝酸盐超标350倍,甚至重量还是用鱼胶、果胶、琼脂粉撑起来的。
目前,全国范围内正在大力整顿燕窝市场。8月15日,浙江省工商局公布了对血燕抽查结果,抽查的3万多盏共计20万克问题血燕中,平均亚硝酸盐含量达4400毫克/千克,最高达11000毫克/千克。根据国家强制性标准《食品安全国家标准食品添加剂使用标准》规定,亚硝酸盐仅允许腌熏肉等制品有微量残留,限量为30毫克/千克,熏制火腿最高残留量也不得超过70毫克/千克。对非有意添加、自然生成的亚硝酸盐,《食品中污染物限量国家标准》规定限量一般为3毫克—5毫克/千克,酱腌菜的限量也仅为20毫克/千克。
“很多加工场用化学药剂除毛,节约了绝大部分人工成本;然后通过加胶、掺水、粘碎等手法,能够把500克原料生产出750克左右的成品。”上述业内人士说。通过专用的胶体(super77等),对燕窝进行涂抹,实现辅助定型、提高品相、增加重量、掩盖瑕疵等多重目的,这已经是燕窝行业内公开的秘密。
血燕亚硝酸盐严重超标
[3]
编辑本段制法
1、碱金属和碱土金属的亚硝酸盐可由等当量的一氧化氮和二氧化氮通入该金属的氢氧化物溶液中便可得。
2、分解硝酸盐可制造出亚硝酸盐和氧气。
编辑本段毒性
毒性概述
值得注意的是,高剂量的亚硝酸盐还是会产生很大毒性。误食了亚硝酸盐会导致亚硝酸盐类食物中毒,
亚硝酸钠
长期使用甚至会导致食道癌和胃癌。而且,科学家目前还缺少临床试验证明亚硝酸盐可以治疗心脏病等疾病。所以,科学家正在积极征集志愿者进行临床试验,并开始寻觅合适的药物生产商负责研发亚硝酸盐类药物。
急性中毒原因
1.将亚硝酸盐误作食盐、面碱等食用。
2.掺杂、使假。
3.投毒。
4.食用了含有大量亚硝酸盐的蔬菜,尤其是不新鲜的叶类蔬菜。
慢性中毒(包括癌变)原因
1.饮用含硝酸盐或亚硝酸盐含量高的苦井水、蒸锅水。
2.食用硝酸盐或亚硝酸盐含量较高的腌制肉制品、泡菜及变质的蔬菜。
中毒机理:
亚硝酸盐为强氧化剂,进入人体后,可使血中低铁血红蛋白氧化成高铁血红蛋白,失去运氧的功能,致使组织缺氧,出现青紫而中毒。
亚硝酸盐中毒症状
1.头痛、头晕、无力、胸闷、气短、心悸、恶心、呕吐、腹痛、腹泻及口唇、指甲、全身皮肤、粘膜紫绀等。
2.全身皮肤及粘膜呈现不同程度青紫色(高铁血红蛋白血症引起的紫绀)。
3.严重者出现烦躁不安、精神萎靡、反应迟钝、意识丧失、惊厥、昏迷、呼吸衰竭甚至死亡。
如何通过变性血红蛋白试验检测亚硝酸盐中毒
1.取病人静脉血3~5毫升,血色呈蓝紫色。
2.离心沉淀,血浆呈淡黄色,说明蓝紫色是细胞本身异常所致。
3.摇匀后在氧气或空气中振摇15分钟,若恢复为鲜红 色则表明原蓝紫色是低铁血红蛋白被氧化所致。
4.通过以上简单的试验,基本上可作出初步判断。
亚硝酸盐中毒的抢救
1.口头医嘱:对于急性中毒事件,应先口头医嘱作常规处理,如吸氧、留取静脉通道、送检等,然后再了
亚硝酸钠
解病史、检查病人,建立病历,以赢得抢救时间。切忌按常规顺序慢慢问病史、书写病历,确诊后才开始作处理往往会延误时间。
2.吸氧:食用腌制蔬菜、熟剩菜等易产生亚硝酸盐,有不法分子从工业用盐中提取的散装食盐更是亚硝酸盐的一大来源,亚硝酸盐是一种氧化剂,可使正常低铁血红蛋白氧化成高铁血红蛋白,失去输氧能力而使组织缺氧。观察所见病人面色发青,口唇紫绀,静脉血呈蓝紫色都是缺氧的表现,因此立即给予吸氧处理。
3.美蓝(亚甲蓝)的应用:是亚硝酸盐中毒的特效解毒剂,能还原高铁血红蛋白,恢复正常输氧功能。用量以每公斤体重1~2mg计算。同时高渗葡萄糖可提高血液渗透压,能增加解毒功能并有短暂利尿作用。
4.对症处理:对于有心肺功能受影响的患者还应对症处理,如用呼吸兴奋剂,纠正心律失常药等。
5.营养支持:病情平稳后,给予能量合剂、维C等支持疗法。
6.洗胃:如果中毒时间短,还应及时予以洗胃处理。
常见的亚硝酸盐有亚硝酸钠和亚硝酸钾,国内有多起误将亚硝酸钠作食盐用,导致急性中毒事件的报道。治疗除及时清除毒物、吸氧外,解毒剂为亚甲蓝(美蓝),重危病人可输新鲜血200~400毫升,必要时,可考虑采用换血疗法。
编辑本段亚硝酸盐的含量测定
测定准备
对大型抢救,医护人员首先要做到的一点是沉着冷静,切忌慌中出错。
由此,测定亚硝酸盐的含量是食品安全检测中非常重要的项目。
部分食品中亚硝酸盐的限量标准(以NaNO2计)
品 名 限量标准mg/kg 品 名 限量标准mg/kg
食盐(精盐)、牛乳粉 ≤2 香肠(腊肠)香肚、酱腌菜、广式腊 肉 ≤20
鲜肉类、鲜鱼类、粮食 ≤3 肉制品、火腿肠、灌肠类 ≤30
蔬菜 ≤4 其他肉类罐头、其他腌制罐头 ≤50
婴儿配方乳粉、鲜蛋类 ≤5 西式蒸煮、烟熏火腿及罐头、西式火腿罐头 ≤70
亚硝酸盐检测仪
说明:
①生活饮用水中常存有微量的亚硝酸盐不能作为测定用稀释液。
②若显色后颜色很深且有沉淀产生或很快退色变成浅黄色,说明样品中亚硝酸盐含量很高,须加大稀释倍数重新测定。
③对超标样品应进行重复实验,有条件时送实验室准确定量。
常温避光保存 有效期18个月,生产日期见包装。
附:
亚硝酸盐快速检测管 使用说明:
方法原理:按照国标GB/T 5009.33做成的速测管,与标准色卡比较定量。
操作方法
1. 食盐中亚硝酸盐的快速检测及食盐与亚硝酸盐的快速鉴别:用袋内附带小勺取食盐1平勺,加入到检测管中,加入蒸馏水或纯净水至1ml刻度处,盖上盖,将固体部分摇溶,10分钟后与标准色板对比,该色板上的数值乘上10即为食盐中亚硝酸盐的含量mg/ kg,(国标规定食盐(精盐)中亚硝酸盐的限量卫生标准应≤2 mg/kg)。当样品出现血红色且有沉淀产生或很快退色变成黄色时,可判定亚硝酸盐含量相当高,或样品本身就是亚硝酸盐。
2. 液体样品检测:直接取澄清液体样品1ml加入到检测管中,盖上盖,将试剂摇溶,10分钟后与标准色板对比,找出与检测管中溶液颜色相同的色阶,
亚硝酸盐检测
该色阶上的数值即为样品中亚硝酸盐的含量mg/L(以NaNO2计)。(牛乳及豆浆也可直接检测,结果不得超过0.25mg/L ,有颜色的液体样品可加入一些活性炭脱色过滤后测定)。
3. 固体或半固体样品检测:取粉碎均匀的样品1.0g或1.0ml至10ml比色管中,加蒸馏水或去离子水(纯净水)至刻度,充分震摇后放置,
取上清液(或过滤或离心得到的上清液)1.0ml加入到检测管中,盖上盖,将试剂摇溶,10分钟后与标准色板对比,该色板上的数值乘上10即为样品中亚硝酸盐的含量mg/ kg,L(以NaNO2计)。如果测试结果超出色板上的最高值,可定量稀释后测定,并在计算结果时乘上稀释倍数(如从10ml比色管中取出1.0mL转入另一支10ml比色管中,加水至刻度,从中取1.0mL加入到检测管中测定,测试结果乘上100(倍稀释)即为样品中亚硝酸盐的含量。
编辑本段尿检
介绍
某些泌尿系统存在的细菌可以将尿中蛋白质代谢产物硝酸盐还原为亚硝酸盐因此测定尿液中是否存在亚硝酸盐就可以快速间接的知道泌尿系细菌感染的情况作为泌尿系感染的筛查试验
临床上尿路感染发生率很高并且有时是无症状的感染在女性病人中尤其如此诊断尿路感染需做尿细菌培养需较长时间和一定条件而尿亚硝酸盐定性实验可以很快的得到结果有助于该病辅助诊断
当明显尿路感染者利用细菌能还原硝酸盐为亚硝酸盐的特性酚类偶联产生红色为阳性反应
尿亚硝酸盐阳性率取决于尿液在膀胱中存留时间大于4小时阳性率可达80%若尿路感染细菌不能使硝酸盐还原为亚硝酸盐或尿在膀胱停留时间较短或尿中缺乏亚硝酸盐也会产生阴性结果阳性结果提示尿中存在细菌数100000/ml以上
正常值:阴性记为(-)
临床意义
亚硝酸盐阳性结果常见于:由大肠杆菌(大肠埃希氏菌)引起的肾盂肾炎其阳性率占到总数的三分之二以上;由大肠埃希菌等肠杆菌科等细菌引起的有症状或无症状的尿路感染膀胱炎菌尿症等。
尿亚硝酸盐试验阴性时并不表示没有细菌感染只是由于某些不具备还原硝酸盐能力的细菌引起的泌尿系感染不能显示阳性这类细菌有不动杆菌等非发酵菌或尿液在膀胱中未能潴留4小时以上。
注意若尿路感染细菌不能使硝酸盐还原为亚硝酸盐或尿在膀胱中存留较短或尿中缺乏硝酸盐也会产生阴性结果。
编辑本段预防措施
1、蔬菜应妥善保存,防止腐烂,不吃腐烂的蔬菜。
2、食剩的熟菜不可在高温下存放长时间后再食用。
3、勿食大量刚腌的菜,腌菜时盐应多放,至少腌至15天以上再食用;但现腌的菜,最好马上就吃,不能存放过久,腌菜时选用新鲜菜。
4、不要在短时间内吃大量叶菜类蔬菜,或先用开水焯5分钟,弃汤后再烹调。
5、肉制品中硝酸盐和亚硝酸盐用量要严格按国家卫生标准规定,不可多加。
6、苦井水勿用于煮粥,尤其勿存放过夜。
7、防止错把亚硝酸盐当食盐或碱面用。
编辑本段亚硝酸盐来源
1、食物中作为发色剂和防腐剂的亚硝酸盐。
2、从食物中添加的硝酸盐转化而来。
3、蔬菜,尤其是从不新鲜的蔬菜中转化而来。
编辑本段亚硝酸盐食用过多处理方法
1、补充液体,尤其是开水或其它透明的液体;
2、补充因上吐下泻所流失的电解质,如钾、钠及葡萄糖;
3、避免制酸剂;
4、先别止泻,让体内毒素排出之后再向医生咨询;
5、毋须催吐
;
6、饮食要清淡,先食用容易消化的食物,避免容易刺激胃的食品 。
鉴于以上原因,国家对食品中的亚硝酸盐残留制定了严格的限量标准,但由于高浓度的亚硝酸盐不仅可改善肉制品的感观色泽,还可大大缩短肉制品的加工时间,因此肉制品亚硝酸盐超标的现象较为普遍。甚至少数不法经营者以病死猪肉先经过双氧水浸泡漂白,然后再添加大量的亚硝酸盐,最后经过加工而达到正常肉制品的色泽效果;还有添加大量亚硝酸盐的腊肉只要经过一夜熏烤就可以达到正常熏烤十几天的色泽和硬度,而且“格外光鲜”。
编辑本段如何减少亚硝酸盐和亚硝基化合物的摄入
•多吃新鲜的蔬菜和肉类。
•低温保存食物,以减少蛋白质分解和亚硝酸盐生成。
•不吃腌腊制品、肠、酸菜等。
•不吃腌制时间在7日左右的咸菜,少吃腌制时间在15日内的咸菜。
•胡椒和辣椒等调味品与盐分开包装。
•经常暴晒粮食,让亚硝基化合物分解。
•不喝长时间煮熬的蒸锅剩水。
可以阻断亚硝基化合物合成的食物:
•含维生素C和维生素E丰富的蔬菜水果。
•大蒜、茶叶。
•食醋。
Friday, February 24, 2012
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