白菜渣可溶性膳食纤维酸法提取工艺优化及理化性质测定

Optimization of Acid Extraction and Physicochemical Properties of Soluble Dietary Fiber from Chinese Cabbage Residue

以大白菜外叶为原料,采用酸法制备白菜渣可溶性膳食纤维(soluble dietary fiber,SDF)。以白菜渣SDF提取率为指标,在单因素试验的基础上,利用Box-Behnken试验设计结合响应面分析对提取工艺进行优化,得到的最优提取工艺参数为:盐酸浓度0.06 mol/L、料液比1∶25(g/m L)、提取温度90℃、提取时间90 min。在此工艺条件下,白菜渣SDF提取率达到了13.65%;化学组成分析结果表明,试样SDF含量为86.21%,含有部分蛋白质和灰分等杂质;白菜渣SDF外观呈淡米黄色粉末,扫描电镜观察到白菜渣SDF粉粒表面粗糙,进一步放大倍数后发现粗糙表面结构呈褶皱状,含有较多孔洞和孔隙;白菜渣SDF持水力和膨胀力分别为14.63 g/g和22.17 m L/g;乳化能力和乳化稳定性分别为48.78%、71.34%;吸附饱和脂肪酸、不饱和脂肪酸能力分别为2.23、1.94 g/g。以上功能性质测定结果表明,白菜渣SDF具有作为乳化剂和保健食品原料的潜力。

The extraction of soluble dietary fiber(SDF) from outer leaves of Chinese cabbage was optimized for maximum SDF yield using combination of single factor method and response surface methodology with Box-Behnken experimental design. The optimum extraction parameters were determined as follows: hydrochloric acid concentration, 0.06 mol/L; material/liquid ratio, 1:25(g/m L); extraction temperature, 90 ℃; and extraction time, 90 min. Under these optimal conditions, the extraction yield of SDF was 13.65%. The chemical composition analysis showed that the purity of the SDF product was 86.21%, which also contained a small amount of protein and ash. The appearance of the SDF was a light beige powder. The microstructure observation showed that SDF powder of cabbage residue exhibited a rough, wrinkled surface with many holes and pores through magnified observation. The water-holding capacity of the SDF from Chinese cabbage leaves was 14.63 g/g, the expansion capacity 22.17 m L/g, and the emulsifying capacity and emulsion stability were 48.78%and 71.34%, respectively. The adsorption abilities for saturated fatty and unsaturated fatty acid were 2.23 and 1.94 g/g, respectively. These functional properties indicated that the SDF from Chinese cabbage residue is a potential emulsifier and functional food ingredient.