Study On The Physico-chemical And Functional Properties Of Sweet Potato Dietary Fiber

Dietary fiber is a complex material composed of cellulose, hemicellulose, lignin, pectin and so on. As an important component of function food, Dietary fiber has broad prospects in the development of functional food. The sweet potato starch production generated a lot of dietary fiber-rich sweet potato residues which has not been fully exploited. That problems not only cause the waste of resources but also cause the serious environment pollution. In this study, the dietary fiber which was extracted from sweet potato residues by physical screening and purified by enzymolysis method, and the sweet potato residues were from Anhui, Beijing Miyun starch processing factory and laboratory preparation. The composition, morphology, physico-chemical properties and functional properties of sweet potato dietary fiber were investigated.Sweet potato dietary fiber which was prepared by traditional technology has larger particle size ,poorer Physico-chemical properties and functional features. It limited the development of function food related of sweet potato dietary fiber, In this study, the sweet potato dietary fiber was modified by jet milling and high-pressure water jet milling grinding method, and then the composition, morphology, physico-chemical properties and functional properties of sweet potato dietary fiber were compared and analyzed. We also studied the breads quality which was added by different levels of sweet potato dietary fiber. The results are as follows:1. The sweet potato residues of Anhui was suitable for extraction of dietary fiber. The sweet potato dietary fiber of Anhui possessed the highest TDF content and SDF content. Furthermore, it has better physicochemical and functional properties.2. Micronization methods could transform IDF to SDF and dissoluble sugar. Moreover, it just cut off the bundle structure of sweet potato dietary fiber, could not damage the chip layered structure of sweet potato dietary fiber. So the particle size of dietary fiber was significantly diminished. Micronization methods particular high pressure water jet could significantly improve the physico-chemical properties and functional characteristics. At the same time, it can enhance the sweet sensory acceptability of dietary fiber.3. The breads with 2%—3% sweet potato dietary fiber had the better sensory acceptability, physical properties and texture characterisitics than the breads which were not added sweet potato dietary fiber. Therefore, we can add a certain amount of sweet potato dietary fiber in the bread in order to keep body healthy.