马铃薯淀粉加工分离汁水中大约含有1.5%蛋白质，本研究分析了超滤法在马铃薯蛋白回收当中的应用，并且通过对实验条件的优化，准确地测定了蛋白酶抑制因子对胰蛋白酶的抑制能力。在实验条件下，研究结果表明：浓缩比为5的情况下，分子截留量分别为10000 MWCO和30000 MWCO的超滤膜包的浓缩液蛋白浓度分别增加到原来的4.35和3.90倍，蛋白质回收率分别为67.61%和62.98%。SDS-PAGE结果表明两个超滤膜包回收的蛋白组成没有什么差异，均包含patatin蛋白和蛋白酶抑制剂组分，但30000 MWCO的超滤膜包孔径较大，水和小分子量物质更容易穿透，浓缩效率高，更加适合于回收马铃薯总蛋白。分子截留量分别为10000 MWCO和30000 MWCO的超滤膜包回收的蛋白胰蛋白酶抑制剂的活力分别为124.38和95.25 TIUs/mg蛋白。超滤法适用于从马铃薯淀粉加工分离汁水中回收天然活性蛋白质。

Potato starch processing water (PSPW) contains about 1.5% protein. The application of ultrafiltration in protein recovery from PSPW was analyzed in this study and the activity of protease inhititors was measured accurately by optimizing the experimental conditions. Under the experimental conditions, the results showed that: the protein concentration of the concentrated solution of ultrafiltration membrane packs of 10,000 MWCO and 30,000 MWCO increased to 4.35 and 3.90 times, respectively, and the protein recovery rates of the two ultrafiltration membrane packs were 67.61% and 62.98%, respectively, in the case of the concentration ratio of 5. SDS-PAGE results showed that there was no difference in protein composition between the two ultrafiltration membrane packs, both of which contained patatin protein and protease inhibitors, but the efficiency of 30000 MWCO was higher, because that the water and small molecules were easier to penetrate, so it was more suitable for the recovery of proteins of the PSPW. The trypsin inhibitor activities of ultrafiltration membrane packs of 10,000 MWCO and 30,000 MWCO were 124.38 and 95.25 mg/mg, respectively. Ultrafiltration is suitable for the recovery of natural active protein from potato starch processing juice.

甘肃省自然科学基金项目（1501RJZA004）；兰州市科技发展计划项目（2016-3-123）；西北民族大学引进人才项目（Z16061）；西北民族大学中央高校基本科研业务费资金资助项目（Y17030）