桔红肉甘薯块根膨大期主要营养成分的变化动态及其相互关系

摘要

In order to study the variation dynamics and mutual relationships of main quality traits of fresh tubers of orange -flesh sweet potato [Ipomoea batatas (L.) Lam] in expanding process, the author respectively sampled the fresh tubers on the 40th, 70th, 100th, and 125th day after transplanting , determined the contents of β-carotene, Fe, Zn, starch, sucrose, fructose and glucose in these tubers , and analyzed the mutual relationships among these nutrients .Theβ-carotene content in the whole growth period increased firstly and then decreased .The variation of protein content showed the tendency of “decreasing-rising”.The vari-ation dynamic of starch content was similar to that of β-carotene content , while its fluctuation was gentler .The changing curve of carbohydrate content was opposite to that of starch content , showing decreasing firstly and then rising .The Fe content decreased rap-idly at first and then reduced slowly .The Zn content was plummeting .The sucrose content in fresh tubers had very significantly neg-ative correlation with β-carotene content , and had significantly positive correlation with fructose content .The starch content had very significantly negative correlation with fructose content , and had significantly positive correlation with Zn content .%为研究桔红肉甘薯在块根膨大过程中鲜薯主要品质性状的变化动态及其相关性。于栽插后40、70、100和125 d等4个时期分别挖根取样，测定鲜薯β－胡萝卜素、铁、锌、淀粉、蔗糖、果糖和葡萄糖含量，并分析其相互关系。β－胡萝卜素含量在整个生育期表现出“升高－降低”的单峰波动曲线；蛋白质含量的变化趋势为“下降－升高”；淀粉含量的变化动态与β－胡萝卜素相似，只是波动趋势较平缓；糖类物质的变化曲线与淀粉正好相反，表现出“降低－升高”的波动趋势；铁元素含量一直在降低，先是快速下降，然后缓慢下降；而锌元素含量则是直线下降。鲜薯蔗糖含量与β－胡萝卜素含量极显著负相关，与果糖含量显著正相关；淀粉含量与果糖含量极显著负相关，与锌元素含量显著正相关。