外文翻译---玉米醇溶蛋白研究进展.docx

XX大学毕业论文外文文献外文文献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 of 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 strong 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, moisture, 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 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 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 can 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 suitable 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 solution 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 lipid 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 extract. 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% protein 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 times 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 the 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, 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 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 taste 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, proline, 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 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, Wangxue 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 preservation 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 deformation, 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 waterproof 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% glycerol 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, carrying 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 ConclusionZein 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 Chinas corn deep processing and comprehensive development rate gap compared with developed countries, 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 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. 7外文译文玉米醇溶蛋白研究进展摘要 本文介绍了玉米醇溶蛋白的组成, 综述了玉米醇溶蛋白在提取, 脱色和应用方面的研究新进展。关键词: 玉米醇溶蛋白；研究；应用玉米醇溶蛋白( zein) 1821年从玉米中分离出来, 从此一直受到科学家的关注。但因其缺少赖氨酸、色氨酸等人体必需氨基酸, 所以其生物学价值低。醇溶蛋白不溶于水限制了其在食品中的应用。过去均作为低价值饲料蛋白出售, 国际上每吨仅200多美元, 国内价2500元左右。醇溶蛋白疏水性高, 具有很强的耐热性和耐脂性, 蛋白中脯氨酸、丙氨酸、亮氨酸多, 醇溶蛋白有覆膜形成性、黏结性、凝胶化性等外观特征, 还有肠溶性和抗氧化特点。在食品工业中, 玉米醇溶蛋白可以作为被膜剂, 即以喷雾方式在食品表面形成一个涂层, 可防潮、防氧化, 从而延长食品货架期。喷在水果上, 还能增加光泽。此外, 还能用于药物的长效囊膜。因此开发醇溶蛋白的新用途, 得到国内外研究工作者越来越多的重视。玉米醇溶蛋白可以从玉米粉中提取, 也可以从玉米分离淀粉后的玉米渣中提取, 后者成本低。从玉米渣中提取醇溶蛋白的商业化生产始于1939年。目前全球的玉米醇溶蛋白主要由美国和日本的公司生产, 依据纯度不同每公斤10 40美元。玉米醇溶蛋白是高商业价值的产品, 但是我国还未能形成规模生产, 相关的研究也较少。本文主要介绍近几年来玉米醇溶蛋白研究所取得的新进展。1. 玉米醇溶蛋白的组成玉米醇溶蛋白, 是玉米中的蛋白质,包括和两种。Zain可溶于体积分数为95%的乙醇溶液，Zain中的组氨酸、精氨酸、脯氨酸、蛋氨酸含量较少。Zain可溶于体积分数为60%的乙醇溶液，由于Zain性质不稳定，易产生沉淀和凝固，不适于工业生产。所以工业上生产中常用Zain。2玉米醇溶蛋白的提取玉米醇溶蛋白可以用乙醇提取, 异丙醇提取和超声波法提取。乙醇提取法用的较多。乙醇提取的一般方法是用90% 95% 的乙醇溶液萃取,加水稀释乙醇到60%再萃取, 离心。但是这样得到的提取物包含醇溶蛋白和较多的玉米脂质, 不能满足利用醇溶蛋白生产膜和制取高纯度蛋白质产品的要求。大部分的脂质可以另外添加正己烷或者乙醇萃取除去, 但是这会增加成本, 且效果不太好。通过多次稀释提取液反复萃取的方法,可以得到蛋白质含量90%以上, 脂质含量10% 以下的提取物。实验证明, 先稀释乙醇到55% , 再稀释提取液到50% 萃取出一定的提取物, 从这部分物质中离心沉淀出醇溶蛋白质, 其中脂质的含量远远低于仅经过一步将乙醇稀释到40% 而萃取出的蛋白质中脂质的含量。以该方法可以生产出纯度较高的玉米醇溶蛋白3.玉米醇溶蛋白的应用3.1抗氧化剂玉米醇溶蛋白自身及水解产物具有抗氧化性。国外研究开发成功将脂肪酸溶解于玉米醇溶蛋白的溶液中进行干燥固定油脂, 例如将亚油酸及4倍其量的醇溶蛋白溶于乙醇中, 喷雾干燥得到的粉末, 有很高的抗氧化性和抗氧化稳定性。将鱼油脂肪酸与2 倍其量的玉米醇溶蛋白溶于80% 乙醇中干燥得到的膜, 单甘油酯、二甘油酯、三甘油酯与玉米醇溶蛋白溶于乙醇中分别成膜,均有很强的抗氧化性。因此, 玉米醇溶蛋白是易氧化的高度不饱和脂肪酸抗氧化及保持抗氧化稳定性的最合适的材料。在油脂食品中作用十分显著,应用潜力巨大。3.2替代口香糖胶基玉米醇溶蛋白替代胶基制成的口香糖有很多优点, 咀嚼后不黏附, 有生物降解性, 易消化。这些性质是人工合成的胶基所没有的。应用玉米醇溶蛋白替代口香糖胶基是扩大醇溶蛋白在其他食品领域应用的途经之一。张钟等研制了玉米醇溶蛋白替代胶基的口香糖, 采用25% 替代量所得的口香糖具有与10