Study On The Extraction Of Dietary Fiber From Wheat Bran And Its Effect On The Gel Properties Of Surimi

Dietary Fiber is called the Seventh Nutrients due to its physiological function, and it has good technological properties. As a kind of functional ingredients added to food is an effective and efficient enhance method. Surimi products are tasted special, loved by consumers, which can be a good carrier food. But now most of researches only focused on the application of DF in baked products, few studies involved in surimi gels fortified with different particle size of insoluble dietary fiber (IDF). There is no report about the effect on surimi gels addition of different solubility DF, so in this paper IDF and SDF were extracted from wheat bran by complex protease, and then the effect on the functional properties of different particle size IDF was studyed. In order to make clear the relationship between physico-chemical properties of DF and surimi gels, the effect of different particle size IDF and different solubility DF on the gel properties of surimi were studyed. To provide the scientific basis for apply DF into surimi gels. The main results were as follows:1.SDF and IDF were extracted respectively, and analyzed the change of holding water capacity and swelling of different particle size IDF. The best condition of extraction of SDF and IDF with enzyme was that 2.0% of alkaline protease, pH7.5, reaction temperature 55℃ and enzymolysis time 2.5h. The purity of IDF was 90.68%, the purity of SDF was 92.26%.The soluble component and the whiteness increased with the IDF size decreased, while swelling and holding water capacity decreased.2.Effect on the properties of surimi gels fortified with different particle size IDF. Holding water capacity of gel with IDF increase, but the effect was not significant; the whiteness gel increase with IDF size decrease. Compared with control, the hardness of the gel firstly increased between 627μm and 270uμm and then decreased between 270μm and 85μm). In addition to the 85μm, hardness of the other groups were significantly higher than controls; Comprised with controls, breaking force and breaking distance of IDF-surimi mixed gel decreased significantly.Breaking force upgrade firstly and then decreased with size decrease, but there was no significant change. The elastic modulus (G’) were significantly higher than the blank group. Added the IDF decreased the content of ionic bonding and hydrophobic interaction, promoted the formation of hydrogen bonds.In this test, the optimum particle size of IDF was 85μm.3.Effect on the properties of surimi gels fortified with different solubility DF was related closely with additive amount. The hardness and water holding capacity increased significantly when additive amount was optimum, while amount was too larger will has negative influence on gel properties adding. The effect of SDF was better than IDF. Compared with the blank control group, the breaking force and breaking distance decreased significantly with IDF, while added 1%-3% SDF, breaking force and breaking distance decreased significantly, but no significant changes between 1% and 3% group. When additive amount was less than 3%, both IDF and SDF can decrased the content of ionic bonding and promote the formation of hydrogen bonds hydrophobic interaction. When additive amount was higher has negative influence on the chemical interactions related to gel formation.