李萍+胡矗垚+舒展+张兰+闫静坤+汪青青

摘 要：采用水提醇沉法提取洋葱水溶性粗多糖，以粗多糖提取率和多糖含量的综合评分为指标，利用正交试验优化提取工艺。结果表明：最佳提取工艺条件为时间3 h，料液比1∶30 g·mL-1，温度90 ℃，物料粉碎度0.25～0.40 mm（筛孔径），在此条件下粗多糖提取率达到5.886%，多糖含量为54.547%。影响粗多糖提取效果的因素次序为：温度>料液比>物料粉碎度>时间，温度的变化对粗多糖提取效果具有显著影响。相同提取条件下，紫皮洋葱粗多糖提取率比黄皮洋葱高出1.681%，多糖含量比黄皮洋葱高出21.429%，紫皮洋葱更适用于粗多糖的提取且营养价值更高。总之，水提醇沉法提取洋葱水溶性粗多糖，成本低廉，操作简便，易实现工业化生产。

关键词：洋葱；水溶性粗多糖；水提醇沉；提取率；多糖含量；工艺优化

中图分类号： 文献标识码： DOI 编码：10.3969/j.issn.1006-6500.2017.

Optimization of Extraction Process of Water-soluble Crude Polysaccharide from Onion

LI Ping， HU Chuyao， SHU Zhan， ZHANG Lan， YAN Jingkun， WANG Qingqing

（College of Basic Science， Tianjin Agricultural University， Tianjin 300384， China）

Abstract：Water extraction and ethanol precipitation method were applied to extract water-soluble crude polysaccharide from onion. Orthogonal experiment was used to optimize extraction process with the integrated score of the extraction rate of crude polysaccharide and polysaccharide content as index. The eesults showed that the optimum extraction conditions were as follows： extraction time 3 h， ratio of material to solvent 1∶30 g？mL-1， extraction temperature 90 ℃， powder granularity of the material was 0.25～0.40 mm， and under these conditions the extraction rate could reach 5.886% and the polysaccharide content was 54.547%. Factors affecting the extraction effect of crude polysaccharide were in the order of extraction temperature> ratio of material to solvent> powder granularity of the material> extraction time， and the extraction temperature had a significant effect on extraction effect. Water-soluble crude polysaccharide extracted from purple onion contained higher extraction rate and polysaccharide content with 1.681% and 21.429% improvement than that from yellow onion， respectively， which indicating that purple onion was more suitable for the extraction of crude polysaccharide and contained higher nutritional value. In conclusion， water extraction and ethanol precipitation method to extract water-soluble crude polysaccharide from onion was simple to operate and easy to realize industrial production with low cost.

Key words：onion；water-soluble crude polysaccharide；water extraction and ethanol precipitation；extraction rate；polysaccharide content；process optimization

植物多糖是存在于植物細胞中的一类大分子物质，具有广泛的生理活性，其中以水溶性多糖最为重要[1]。洋葱是百合科草本，高产耐贮，供应期长，具有降血糖、预防心血管疾病、防癌、抗癌等药用价值[2]，是很好的食疗品，也是食品加工业的重要原料。研究表明，洋葱中含有丰富的多糖类物质[3-4]，然而大量洋葱加工废料的产生对环境造成很大影响，寻找简单易行的多糖提取方法，对洋葱加工后的废料进行利用，可以减少环境污染并创造经济效益。

多糖的提取方法有水提醇沉法[5]、酶解法[6]、超声波法[7]和微波法[8]等。酶解法条件温和，提取率高，但提取温度过高时会对酶的活性产生影响；超声波……