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

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/mL）、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 mL/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。

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

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/mL); 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 mL/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.