贮藏期不同类型甘薯块根营养品质与淀粉特性变化

贮藏过程中甘薯的品质会发生变化,为深入研究不同贮藏时期甘薯品质和淀粉特性的变化规律,分析淀粉型甘薯ZH1042、鲜食型甘薯ZZ1-358和对照品种心香在贮藏期间的营养品质与淀粉特性变化。结果表明:随着贮藏时间的延长,不同类型甘薯的品质和淀粉特性变化规律不同。淀粉型甘薯在贮藏过程中失水率和腐烂率最高,心香在整个贮藏期的腐烂率最低。3个甘薯品种(系)的总淀粉酶活性和β-淀粉酶活性随着贮藏时间的延长呈现先上升后下降再上升的趋势且差异显著。ZH1042淀粉含量呈现先下降后上升的趋势,可溶性糖含量和蛋白质含量总体呈现先上升后下降趋势,整个贮藏期可溶性糖含量变化不显著,而蛋白质含量在贮藏100 d后显著下降。ZZ1-358淀粉含量呈现先下降后上升趋势,可溶性糖含量呈下降趋势,而蛋白质含量却先上升后下降又上升。心香的淀粉含量在贮藏100 d后显著上升,可溶性糖含量随着贮藏时间的延长而降低,蛋白质含量则随着贮藏时间的延长呈现先升高后降低再升高的趋势,差异显著,由此可见,甘薯中淀粉含量的高低直接影响甘薯的可溶性糖和蛋白质含量。贮藏70~100 d,不同类型甘薯材料提取的淀粉纯度最高,最高黏度、最终黏度、回复值和热浆黏度在甘薯贮藏100 d时显著下降,甘薯中淀粉含量的高低能够直接影响可溶性糖和蛋白质含量,贮藏会改变甘薯淀粉X射线的衍射强度但不改变其晶体结构,贮藏时间不宜超过130 d。

Changes of nutritional quality and starch properties of different types of sweet potato roots during storage

The quality of sweet potato changes during storage. In order to study of the changes of sweet potato quality and starch characteristics during different storage periods, changes in nutritional quality and starch properties of starchy sweet potato ZH1042, fresh food sweet potato ZZ1-358 and control variety Xinxiang during storage were analyzed. The results showed that: changes in quality and starch characteristics of different types of sweet potato varieties were different with time extension. The starchy sweet potato had the highest water loss rate and decay rate during storage, while Xinxiang had the lowest decay rate during the entire storage period. The total amylase activity and β-amylase activity of the three sweet potato varieties (lines) showed a trend of first rising, then falling and then rising with the extension of storage time, and differences were significant. The starch content of ZH1042 decreased first and then increased. Soluble sugar content and protein content generally increased first and then decreased. Content of soluble sugar did not change significantly before and after the storage period, while protein content decreased significantly after 100 days of storage. Starch content of ZZ1-358 first decreased and then increased, soluble sugar content decreased, while the protein content first increased, then decreased and then increased. Starch content of Xinxiang increased significantly after storage for 100 days, soluble sugar content decreased with extension of storage time, and protein content showed a trend of first increase, then decrease and then increase with extension of storage time, the difference was significant. This showed that level of starch content in sweet potato directly affected content of soluble sugar and protein in sweet potato. During the storage period of 70-100 d, the starch extracted from different types of sweet potato materials had the highest purity. The highest viscosity value, final viscosity value, recovery value and hot pulp viscosity value would decrease significantly when the sweet potato was stored for 100 d. The starch content in the sweet potato could directly affecting soluble sugar and protein content, storage would change X-ray diffraction intensity of sweet potato starch but not its crystal structure. The storage time of most varieties could not exceed 130 d.