藜麦麸皮膳食纤维发酵工艺优化及其理化性质与结构特征研究

Optimization of fermentation conditions and physicochemical properties and structural feature of quinoa bran dietary fiber

为了提升藜麦麸皮的利用率,改善其功能特性,该研究以藜麦麸皮为原料,采用黑曲霉(Aspergillus niger)发酵改性藜麦麸皮膳食纤维。以可溶性膳食纤维(SDF)得率为响应值,通过单因素和响应面试验优化其发酵工艺条件,并对改性前后膳食纤维理化性质及结构特征进行分析。结果表明,最佳发酵工艺条件为料液比1∶20(g∶mL)、接种量10%、发酵时间96 h。在此优化条件下,可溶性膳食纤维得率达24.8%。与未改性的藜麦麸皮膳食纤维相比,改性后藜麦麸皮可溶性膳食纤维的持水力(WHC)、持油力(OHC)、吸水膨胀力(WSC)、阳离子交换能力(CEC)分别提高74.29%、47.35%、32.73%、115.8%。傅里叶变换红外光谱(FT-IR)分析结果表明,改性后可溶性膳食纤维中官能团数量增加,但未产生新的官能团。

In order to improve the utilization of quinoa bran and improve its functional properties,using quinoa bran as raw materials,quinoa bran dietary fiber was modified by fermentation with Aspergillus niger.With the yield of soluble dietary fiber(SDF)as the response value,the fermentation process conditions were optimized by single factor and response surface tests,the physicochemical properties and structural feature of dietary fiber before and after modification were analyzed.The results showed that the optimal fermentation process conditions were solid and liquid ratio 1∶20(g∶ml),inoculum 10%and fermentation time 96 h.Under the optimized conditions,the soluble dietary fiber yield reached 24.8%.Compared with the unmodified quinoa bran dietary fiber,the water holding capacity(WHC),oil holding capacity(OHC),water swelling capacity(WSC)and cation exchange capacity(CEC)of the modified quinoa bran soluble dietary fiber were increased by 74.29%,47.35%,32.73%and 115.8%,respectively.Fourier transform infrared spectrum(FT-IR)analysis results showed that the number of functional groups in soluble dietary fiber increased after modification,but no new functional groups were produced.