酸法提取苹果渣中的果胶及其性质分析

Extraction of pectin from apple pomace by acid and analysis of its property

采用酸法提取苹果渣中的果胶,并以单因素试验为基础,通过响应面法优化其提取工艺条件。结果表明,酸法提取苹果渣果胶的最佳工艺条件为:盐酸调节p H值1.5,温度100℃,时间2 h,固液比1∶14(g∶m L)。在上述最佳条件下,苹果渣中粗果胶得率为33.12%,果胶提取率为19.65%。4个因素对粗果胶得率的影响顺序为:p H值>温度>时间>固液比。酸法提取果胶的分子质量主要分布在165.92 k Da、5.83 k Da与0.45 k Da范围;酯化度为60.90%,属于高酯果胶;半乳糖醛酸含量为70.48%,所提取的果胶纯度相对较高。

The pectin was extracted from apple pomace by acid process, and the conditions were optimized by response surface methodology based on the single factor experiments. The results showed that the optimal acid extraction conditions of pectin from the apple pomace were pH 1.5 by hydrochloric acid adjustment, temperature 100 ℃, time 2 h, solid-liquid ratio 1∶14(g∶ml). Under these optimal conditions, the yield of crude pectin from apple pomace was 33.12%, while the extraction rate of pectin from apple pomace was 19.65%. The factors affecting the crude pectin yield in order was pH, temperature, time, solid-to-liquid ratio. The molecular weight of the pectin obtained was mainly distributed at 165.92 kDa, 5.83 kDa, and 0.45 kDa. The degree of esterification was 60.90%, which meant it was the high methoxyl pectin. The content of galacturonic acid was 70.48%,which meant the purity of the pectin by acid extraction was relatively higher.