Researches On Zein About Extraction By Ultrasound, Modification And Medicinal Release Performance

China is the second largest corn-produce country with 1100 billion kg each year. Corn, as one of the three major cereal crops in the world, is the most important food and industrial corps. To improve its additional value, the main way comes from the refined processing of corn. The major industrial production was corn starch. With complex utilization of corn, its additional value can be increased by 8 times. Corn gluten meal (CGM), the major protein coproducts from corn processing, contained about 60% protein with one-half of zein. As the absence of tryptophane and lysine, zein has lower nutritive value for food. However, as zein's insolubility in water and easy forming a film, the main focus since the mid-20^th century has been on its possible utilization as an industrial polymer. By now, zein is the unique protein with commercial applications in nonfood fields.However, since zein processing consumes a large sum of organic solvent and to recover this organic solvent will consume amount of hot energy, zein has a high production cost with prices varying from $(US) 10-40 per kg which limits its widespread utilization. This paper will research zein on lower cost production, modification and applications in pharmaceutical industry. A step achievement was gained as follows:1) The effects of ultrasonic treatment conditions such as the power and frequency of ultrasonic and the material of containers on extraction rate of corn yellow pigment and zein was researched. A technological flow sheet to extract zein economically and efficiently from CGM was designed. The products has a higher purity with 92.39% of zein and with light-yellow color. This method has reached the domestic leading level, and can be suitable for commercial production.2) According to the experimental results, zein solution with 80% ethanol can be easily form a film which can be separated automaticly on the smooth surface of polythene and polypropylene vessel. When the ethanol content is blow 60%(v/v) or above 90%(v/v), zein solution can't form a film. 10% of zein solution with ethanol content between 80%-90% has the best effect for forming a film.However, pure zein film can't be put into practice because of its lower tensile strength, poor water-proof ability and flexibility. In order to improve its mechanic ability, zein should be modified by plasticizer. The experimental results indicated that with the addition of 3% oleic acid, the tensile strength as well as the elongation rate of...