好食脉孢霉发酵麦麸制备可溶性膳食纤维及其理化性质

采用好食脉孢霉对小麦麸皮进行固态发酵制备可溶性膳食纤维（Soluble dietary fiber，SDF），通过单因素结合响应面法Box-Behnken探究发酵过程中含水量、接种量、发酵温度、发酵时间对可溶性膳食纤维得率的影响，确定培养基的最佳发酵条件。同时对发酵过程中纤维素酶活性和木聚糖酶活性进行测定，并研究发酵前后SDF的理化性质。结果表明:当发酵温度为29℃、接种量为11%（v/w）、含水量为74%（v/w）、发酵时间为83.5 h时SDF得率最高，为13.41%，比发酵前提高了1.05倍。发酵过程中纤维素酶活性与木聚糖酶活性均与SDF得率呈正相关。发酵后SDF溶解性、吸附葡萄糖能力、吸附胆固醇能力（pH=2和pH=7）和DPPH清除能力比发酵前分别提高了1.14、1.76、5.36、4.61和1.62倍，为麦麸SDF作为食品添加剂提供理论基础。

Preparation and Physicochemical Properties of Soluble Dietary Fiber(SDF)from Wheat Bran Fermented by Neurospora sitophila

Soluble dietary fiber(SDF)was prepared by solid fermentation of wheat bran by Neurospora sitophila.The effect of water content,inoculation amount,fermentation temperature and time on SDF yield of wheat bran were studied by the single factor combined with response surface method and the optimum fermentation conditions were obtained.Meanwhile,the activities of cellulase and xylanase in the fermentation process were determined,and the physical and chemical properties of wheat bran SDF were studied.The results showed that the optimum fermentation temperature was 29℃,the optimum inoculation amount was 11%(v/w),the optimum water content was 74%(v/w),the optimum fermentation time was 83.5 h and 13.41%SDF was extracted,which was 1.05 times higher than that of un-fermented wheat bran.The activities of cellulase and xylanase were positively correlated with the yield of SDF during the fermentation process.After fermentation,solubility,glucose adsorption ability,cholesterol adsorption ability(pH=2 and pH=7)and DPPH scavenging ability of wheat bran SDF were increased by 1.14,1.76,5.36,4.61 and 1.62 times respectively.These results provided a theoretical basis for wheat bran SDF as a food additive.