外文翻譯---玉米醇溶蛋白研究進(jìn)展

1、.XX大學(xué)畢業(yè)論文外文文獻(xiàn)外文文獻(xiàn)The zein study progressAbstract This paper introduces the composition of the zein, zein extraction, bleaching, and the application of research.Keywords: zein protein; applicationZein (zein) 1821 isolated from corn, and from this has been the concern of scientists. However, because o

2、f the lack of lysine, tryptophan and other essential amino acids, so its biological value. Gliadin insoluble in water limits its application in food. Are sold as low-value feed protein, only 200 U.S. dollars per ton on the international, the domestic price of 2,500 yuan. Gliadin hydrophobic, has a s

3、trong heat resistance and lipid, protein proline, alanine, leucine, gliadin film formation, adhesion, gel resistance Exterior features, enteric and antioxidant characteristics. In the food industry, zein can be used as a film former, that is to spray a coating is formed in the surface of the food, m

4、oisture, oxidation, thereby extending the shelf-life. Sprayed on the fruit, but also increase the gloss. In addition, but also the long-term for drug capsule. Therefore, the development of new uses of gliadin to get more and more attention of researchers at home and abroad.Zein can be extracted from

5、 corn flour, can also be extracted from corn corn residue after the separation of starch and the low cost of the latter. Extracted from corn residue gliadin commercial production began in 1939. Current global zein produced mainly by the United States and Japan, according to the purity of $ 1040 per

6、kilogram. Zein is a product of high commercial value, but China also failed to form the scale of production, less related research. This paper describes the new progress made in recent years zein Institute.1. The composition of the zeinZein, corn proteins, including both alpha and beta. alpha-Zain c

7、an be dissolved in the volume fraction of 95% ethanol solution of alpha-Zain histidine, arginine, proline, methionine content of less. beta-Zain can be dissolved in a volume fraction of 60% ethanol solution, due to the unstable beta-Zain nature, prone to precipitation and solidification, is not suit

8、able for industrial production. Therefore, the industrial production of commonly used alpha-Zain.2.Extraction of zeinextracted with ethanol, isopropanol extraction and ultrasonic extraction. Ethanol extraction method is used more. The ethanol extract of the general method is to use 90% 95% ethanol s

9、olution was extracted, diluted with water 60% ethanol to re-extraction, centrifugation. However, the extract thus obtained contains the gliadin and more corn lipid, can not meet the requirements of the production of film and the preparation of gliadin protein product of high purity. Most of the lipi

10、d addition of n-hexane or ethanol was removed by extraction, but this will increase the cost, and the effect is not very good. The method through multiple dilution of the extract was repeatedly extracted, can be obtained more than 90% of the protein content below 10% of the lipid content of the extr

11、act. Experiments show that the first diluted with ethanol to 55%, and then the extract was diluted to 50% extract extracted from this portion of the material was pelleted by centrifugation gliadin protein, wherein the lipid content is much lower than after only one step will ethanol diluted to 40% p

12、rotein extracted lipid content. In this method can produce a high purity zein3 zein applications3.1 antioxidants Zein hydrolyzate with antioxidant activity. Global Research successfully developed a fatty acid dissolved in a solution of zein and dried fixed oils, for example, linoleic acid and 4 time

13、s the amount of gliadin, the spray-dried powder obtained was dissolved in ethanol, has a high resistance oxidation and oxidation stability. The fish oil fatty acids with 2 times the amount of zein dissolved in 80% ethanol and dried to obtain a film, monoglycerides, diglycerides, triglycerides and th

14、e zein is dissolved in ethanol, respectively, film, both strong antioxidant activity. Accordingly, the zein is easily oxidized in the highly unsaturated fatty acid Antioxidant and maintain stability against oxidation of the most suitable materials. Very significant role in the oils and fats in foods

15、, many potential applications.3.2 Alternate gum baseZein alternative made of gum base has many advantages, chewing gum adhesion, biodegradable, easy to digest. These properties are not synthetic gum base. Application of cornGliadin alternative to chewing gum base is expanding gliadin applications in

16、 other areas of food via. The Zhang Zhong developed of zein Alternate gum base chewing gum, using a 25% substitution of the resulting chewing gum having a similar nature with 100% of the gum base chewing gum, both preferably viscoelastic and hardness, a long time to chew characteristics, but also ta

17、ste like chewing gum, and also having a nutritional, partially digestible characteristics. In addition, the researchers also developed a zein, soy protein isolate and concentrated aloe juice made of nutrition and health care chewing gum.3.3 Perishable roleZein amino terminus with leucine, alanine, p

18、roline, and other non-polar hydrophobic group, and therefore has a strong hydrophobicity, which was dissolved in ethanol solution can be made of an edible coating film . Such membranes in the case of without adding any crosslinking agents, tanning agents, with a good moisture resistance, such a film

19、 forming speed is faster, the storage stability under high-temperature and high-humidity conditions, good barrier properties against oxygen and carbon dioxide, and have a certain antibacterial function. Currently, fresh meat coating material chitosan, soy protein, wheat gluten, carrageenan gum, Wang

20、xue Rong first zein as a coating Ingredients beef fresh strawberries fresh strawberries very thin skin, in harvesting and transportation process vulnerable to microbial infection and dehydration fast, easy to lose their luster, the decline in the value of the goods. Has yet to find the ideal preserv

21、ation methods, equality zein plastic wrap strawberry fresh experiments. Composite preservative: gliadin 1.75%, 0.3% sucrose, 0.18% glycerol, and supplemented with 0.02% emulsifiers and preservatives, preservation effect is better.3.4 candy shelfCandy deterioration phenomenon is water-absorbing defor

22、mation, zein film has a water resistance coating candy enhance the appearance of better shape retention. This edible film coating also avoids the need to deal with the problem of plastic packaging materials. Wenjing study found that oleic acid and glycerol, shellac complex protein membrane waterproo

23、f best viewed from the outside coated with oleic acid and shellac membrane protein epidermal best, better shape retention, enjoy a taste changed little Paul fragrance than ideal, not the highest water absorption of the coating. The best edible composite wrap film, preferably the ratio of 0.4mL3% gly

24、cerol 0.3mL oleic acid, 0.3mL shellac, 10 ml of 10% gliadin, at 40 ° C under the film formation3.5 Drug Delivery MaterialsIn recent years, the microsphere technique is widely used in the treatment of many diseases the microsphere drug concentration of the drug in the blood can be maintained, ca

25、rrying the drug to reach a particular cell or tissue. A wide range of artificial and natural biodegradable polymer is used for the production of microspheres. Zein can be formed a hard, smooth, hydrophobic and antibacterial film being actively developed in the wall material made of microspheres.4 Co

26、nclusionZein has a unique nature, has many potential applications in food, pharmaceuticals and other high commercial value. China is corn-producing countries, rich in raw materials. But the degree of China's corn deep processing and comprehensive development rate gap compared with developed coun

27、tries, there is no large-scale production of zein, this is indeed very regrettable. Zein development applications depend primarily on the the gliadin extraction and purification, to find more efficient and economical extraction method is a priority, to open up the field of application of the gliadin

28、 and further tap its commercial value is also very important. These have to rely on scientists joint efforts, believe the zein industry in the near future there will be a significant contribution to the economy.; 8外文譯文玉米醇溶蛋白研究進(jìn)展摘要 本文介紹了玉米醇溶蛋白的組成, 綜述了玉米醇溶蛋白在提取, 脫色和應(yīng)用方面的研究新進(jìn)展。關(guān)鍵詞: 玉米醇溶蛋白；研究；應(yīng)用玉米醇溶蛋白(

29、zein) 1821年從玉米中分離出來, 從此一直受到科學(xué)家的關(guān)注。但因其缺少賴氨酸、色氨酸等人體必需氨基酸, 所以其生物學(xué)價(jià)值低。醇溶蛋白不溶于水限制了其在食品中的應(yīng)用。過去均作為低價(jià)值飼料蛋白出售, 國際上每噸僅200多美元, 國內(nèi)價(jià)2500元左右。醇溶蛋白疏水性高, 具有很強(qiáng)的耐熱性和耐脂性, 蛋白中脯氨酸、丙氨酸、亮氨酸多, 醇溶蛋白有覆膜形成性、黏結(jié)性、凝膠化性等外觀特征, 還有腸溶性和抗氧化特點(diǎn)。在食品工業(yè)中, 玉米醇溶蛋白可以作為被膜劑, 即以噴霧方式在食品表面形成一個(gè)涂層, 可防潮、防氧化, 從而延長食品貨架期。噴在水果上, 還能增加光澤。此外, 還能用于藥物的長效囊膜。因此開

30、發(fā)醇溶蛋白的新用途, 得到國內(nèi)外研究工作者越來越多的重視。玉米醇溶蛋白可以從玉米粉中提取, 也可以從玉米分離淀粉后的玉米渣中提取, 后者成本低。從玉米渣中提取醇溶蛋白的商業(yè)化生產(chǎn)始于1939年。目前全球的玉米醇溶蛋白主要由美國和日本的公司生產(chǎn), 依據(jù)純度不同每公斤10 40美元。玉米醇溶蛋白是高商業(yè)價(jià)值的產(chǎn)品, 但是我國還未能形成規(guī)模生產(chǎn), 相關(guān)的研究也較少。本文主要介紹近幾年來玉米醇溶蛋白研究所取得的新進(jìn)展。1. 玉米醇溶蛋白的組成玉米醇溶蛋白, 是玉米中的蛋白質(zhì),包括和兩種。Zain可溶于體積分?jǐn)?shù)為95%的乙醇溶液，Zain中的組氨酸、精氨酸、脯氨酸、蛋氨酸含量較少。Zain可溶于體積分?jǐn)?shù)

31、為60%的乙醇溶液，由于Zain性質(zhì)不穩(wěn)定，易產(chǎn)生沉淀和凝固，不適于工業(yè)生產(chǎn)。所以工業(yè)上生產(chǎn)中常用Zain。2玉米醇溶蛋白的提取玉米醇溶蛋白可以用乙醇提取, 異丙醇提取和超聲波法提取。乙醇提取法用的較多。乙醇提取的一般方法是用90% 95% 的乙醇溶液萃取,加水稀釋乙醇到60%再萃取, 離心。但是這樣得到的提取物包含醇溶蛋白和較多的玉米脂質(zhì), 不能滿足利用醇溶蛋白生產(chǎn)膜和制取高純度蛋白質(zhì)產(chǎn)品的要求。大部分的脂質(zhì)可以另外添加正己烷或者乙醇萃取除去, 但是這會(huì)增加成本, 且效果不太好。通過多次稀釋提取液反復(fù)萃取的方法,可以得到蛋白質(zhì)含量90%以上, 脂質(zhì)含量10% 以下的提取物。實(shí)驗(yàn)證明, 先稀釋

32、乙醇到55% , 再稀釋提取液到50% 萃取出一定的提取物, 從這部分物質(zhì)中離心沉淀出醇溶蛋白質(zhì), 其中脂質(zhì)的含量遠(yuǎn)遠(yuǎn)低于僅經(jīng)過一步將乙醇稀釋到40% 而萃取出的蛋白質(zhì)中脂質(zhì)的含量。以該方法可以生產(chǎn)出純度較高的玉米醇溶蛋白3.玉米醇溶蛋白的應(yīng)用3.1抗氧化劑玉米醇溶蛋白自身及水解產(chǎn)物具有抗氧化性。國外研究開發(fā)成功將脂肪酸溶解于玉米醇溶蛋白的溶液中進(jìn)行干燥固定油脂, 例如將亞油酸及4倍其量的醇溶蛋白溶于乙醇中, 噴霧干燥得到的粉末, 有很高的抗氧化性和抗氧化穩(wěn)定性。將魚油脂肪酸與2 倍其量的玉米醇溶蛋白溶于80% 乙醇中干燥得到的膜, 單甘油酯、二甘油酯、三甘油酯與玉米醇溶蛋白溶于乙醇中分別成膜,均有很強(qiáng)的抗氧化性。因此, 玉米醇溶蛋白是易氧化的高度不飽和脂肪酸抗氧化及保持抗氧化穩(wěn)定性的最合適的材料。在油脂食品中作用十分顯著,應(yīng)用潛力巨大。3.2替代口香糖膠基玉米醇溶蛋白替代膠基制成的口香糖有很多優(yōu)點(diǎn), 咀嚼后不黏附, 有生物降解性, 易消化。這些性質(zhì)是人工合成的膠基所沒有的。應(yīng)用玉米醇溶蛋白替代口香糖膠基是擴(kuò)大醇溶蛋白在其他食品領(lǐng)域應(yīng)用的途經(jīng)之一。張鐘等研制了玉米醇溶蛋白替代膠基的口香糖, 采用25% 替代量所得的口香糖具有與