洋蔥水溶性粗多糖的提取工藝優化

李萍+胡矗垚+舒展+張蘭+閆靜坤+汪青青

摘 要：采用水提醇沉法提取洋蔥水溶性粗多糖，以粗多糖提取率和多糖含量的綜合評分為指標，利用正交試驗優化提取工藝。結果表明：最佳提取工藝條件為時間3 h，料液比1∶30 g·mL-1，溫度90 ℃，物料粉碎度0.25～0.40 mm（篩孔徑），在此條件下粗多糖提取率達到5.886%，多糖含量為54.547%。影響粗多糖提取效果的因素次序為：溫度>料液比>物料粉碎度>時間，溫度的變化對粗多糖提取效果具有顯著影響。相同提取條件下，紫皮洋蔥粗多糖提取率比黃皮洋蔥高出1.681%，多糖含量比黃皮洋蔥高出21.429%，紫皮洋蔥更適用于粗多糖的提取且營養價值更高。總之，水提醇沉法提取洋蔥水溶性粗多糖，成本低廉，操作簡便，易實現工業化生產。

關鍵詞：洋蔥；水溶性粗多糖；水提醇沉；提取率；多糖含量；工藝優化

中圖分類號： 文獻標識碼： DOI 編碼：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類大分子物質，具有廣泛的生理活性，其中以水溶性多糖最為重要[1]。洋蔥是百合科草本，高產耐貯，供應期長，具有降血糖、預防心血管疾病、防癌、抗癌等藥用價值[2]，是很好的食療品，也是食品加工業的重要原料。研究表明，洋蔥中含有豐富的多糖類物質[3-4]，然而大量洋蔥加工廢料的產生對環境造成很大影響，尋找簡單易行的多糖提取方法，對洋蔥加工后的廢料進行利用，可以減少環境污染并創造經濟效益。

多糖的提取方法有水提醇沉法[5]、酶解法[6]、超聲波法[7]和微波法[8]等。酶解法條件溫和，提取率高，但提取溫度過高時會對酶的活性產生影響；超聲波……