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 a。