淀粉加工型甘薯茎尖的成分分析与利用研究

系统地筛选了甘薯茎尖蛋白质最适的提取酶解条件,比较了淀粉加工型和蔬菜专用型甘薯茎尖的营养成分,研究结果表明:用新鲜甘薯茎尖质量2倍体积的0.1%NaHSO₃溶液、30 ℃下搅拌30 min,水溶性蛋白质的提取率可达52%;在此条件下加入木瓜蛋白酶、50 ℃下搅拌水解4 h,水溶性蛋白质的提取率可提高到75%,茎尖蛋白质的水解度可达24.8%.该方法制备的富含功能多肽的甘薯茎尖粉末的蛋白质、游离氨基酸和黄酮类物质的质量分数分别为24.19%、5.41%和3.31%,与蔬菜专用型甘薯茎尖制备的产品无显著差异.该研究开发了利用淀粉加工型甘薯茎尖制备富含营养和功能多肽的保健食品的工艺,为利用田间废弃的甘薯茎尖开辟了新的途径.

The Composition and Utilization of Shoot Tips of Sweet Potatoes for Starch Purpose

The optimal conditions for extracting protein from the shoot tips of sweet potatoes are systematically screened and the nutrient compositions in the shoot tips of sweet potatoes for starch purpose and those for vegetable purpose are compared. As the results show, when the shoot tips of fresh sweet potatoes were stirred in 0.1% NaHSO₃ solution of 2 times volume at 30 ℃ for 30 min, the extraction rate for water-soluble protein was 52%; under these conditions, when papain was added and the mixture was hydrolyzed at 50 ℃ for 4 h, the extraction rate for water-soluble protein was increased to 75% and the proteolysis degree of shoot tips was 24.8%. With this method, the content of protein, free amino acid and flavonoids in the shoot tip powder were 24.19%, 5.41% and 3.31%, respectively. There was no significant difference in these aspects between the products prepared from the shoot tips of sweet potatoes for vegetable purpose and those for starch purpose. This study has opened up a feasible way for using the sweet potato shoot tips abandoned in the field.