| Dietary fiber (DF) is the sum of nonstarch polysaccharides and lignins in food. DF is a kind of essential carbohydrate which is not digested easily by digestive enzyme and beneficial to health. Because intake of dietary fiber may be associated with a number of diseases such as constipation, obesity, high blood fat, diabetes etc, it is called seventh nutrient by many nutritionists.Dietary fiber includes soluble dietary fiber and insoluble dietary fiber. Health protection function of soluble fiber is very strong. Soluble content of common dietary fiber is very low and its function is not obvious. The purpose of this experiment is to improve the soluble content of corn dietary fiber and obtain high quality dietary fiber.Corn skin as the material in this study is a kind of by-product which comes from corn starch factory. High physiology activity and excellent quality corn dietary fiber can be produced using this material through extrusion.Corn dietary fiber (CDF) was obtained after a series of process: washing, cleaning, drying, milling. Total dietary fiber of this kind of CDF is over 80%. But the content of soluble dietary fiber is lower than 3%. The character of physics and chemistry of this kind of dietary fiber is bad and there is not obvious physiology activity.The optimum technology of extrusion was sifted out through analyzing the character of physics and chemistry and character of processing science and physiology activity test of the samples which were treated by different condition. Results show that the quality of extruded corn dietary fiber is better than non-extruded one.The optimum technology of extrusion was sifted out through contrast test. The temperature is 150 ℃ and the water content of material is 50%. The content of soluble dietary fiber of the extruded production increased from 2.7% to 14.7% and other character was improved obviously. It is concluded by analysis that the extruding temperature is the main factor, and the water content of material is not essential. The water content of material was increased with the extruding temperature, or the fiber was not extruded easily and burnt easily.Through analyzing, it is known that the function and character of CDF was improved greatly by extrusion. Its soluble dietary fiber increased 5.4 times, capacity of expending increased 2.8 times and capacity of keeping water increased 2 times, capacity of combining water increased 2 times. Adding 7% extruding corn dietary fiber, the character of dough was improved in a certain sense. In bread technology, its best amount is 7% and its dimension is 0.147mm. The quality of this kind of bread is fine and it is beneficial to health. It was concluded by analyzing serum cholesterol level of rats, total cholesterol of rats, fed extruded corn dietary fiber reduced 37.1%, low density lipoprotein cholesterol reduced 35.6%, and total glyceride reduced 36.9%. So it was36.9%. So it was proved that the extruded corn dietary fiber could prevent many diseases.This kind of extruded corn dietary fiber could be added to a variety of common foods and functional foods. If this kind of dietary fiber is used extensively by all the people, the everyday diet structure could be improved and the incidence of a disease could be reduced. Because of simple technology and low cost and high profit, this kind of production suits to scale manufacture. Not only it is beneficial to people's health but also it adjusts the comprehensive utilization of the corn by-product and it increases economic benefits of deep corn processing and drives development of corn economy. |
PDF Full Text Request