Research Of Insoluble Dietary Fiber From Water Bamboo Shell

Dietary fibre (DF) is a complex material composed of cellulose,hemicellulose,lignin,pectinand so on. As an important component of function food, dietary fibre has attracted more and moreattention. As a byproduct of water bamboo, water bamboo shell contains plenty of dietary fibrebut it has not yet been fully used. Insoluble dietary fibre (IDF) is the primary component of DFand exist in many raw materials.This thesis adopts the chemical method to produce the IDF from the water bamboo shell andthe best processing by the orthogonal design. The optimal processing of bleaching of IDF has beenobtained by the means of hydrogen peroxide and microwave-assisted bleaching with the materialof IDF. The effect of temperature of entironment and size of granularity of dietary fibre on thecharacteristic of dietary fibre were analysed. The results are as follows:1. The concentration of H₂SO₄ had significant influence on extraction of dietary fibre. Theoptimal conditions for extraction IDF from water bamboo shell were that: the concentration ofNaOH was 1.0mol/L, the rate of raw material to water was 1:8,the immersion time was 100minutes and the soaking temperature was 40℃. Then the material was soaked in the H₂SO₄ atpH=2, extracted for 120 minutes in 60℃, washed to neutral, dried for 4hrs keep in 65℃, andcomminuted in the end.2. Experimental results indicated that the concentration of H₂O₂ would significantly affect theIDF bleaching. The most optimal conditions of IDF bleaching were that: the solid-liquid ratio was1:20, the concentration of H₂O₂ was 4%, the deal tmperature was 60℃at pH=12 for 3hrs. The bestoptimal of microwave-assisted bleaching were that: solid-liquid ratio was 1:20, the concentrationof H₂O₂ was 4%, the power of microwave was 800w, and the time for processing was 120s.3. Environment temperature and granularity of IDF have significantly influence on theproperty of IDF. The swelling capacity,water holding capacity,oil holding capacity will increaseas the granularity became smaller, but excess comminution will made them descend; inaddition, water binding capacity decreased as the granularity became smaller. Under highertemperature, the swelling capacity and water holding capacity are better, but oil hodling capacityand water binding capacity are reverse.