不同生育期甘薯块根淀粉糊化特性的差异

Variation in Root Starch Gelatinization Characteristics During the Growth and Development of Sweetpotato

采用差示扫描量热分析仪(DSC)和淀粉粘度速测仪(RVA)分析了 3 个甘薯品种(系)在块根发育过程中淀粉糊化特性的变化。结果表明,随甘薯生育期的延长,3 个品种的淀粉率都呈下降趋势,但直链淀粉率的变化则因品种而异。早期收获,徐薯 18 和浙大 9201 的直链淀粉率表现较高,而浙 3449 则较低。随生育期延长,DSC糊化峰向低温方向移动,且峰宽增大、峰逐渐消失,其糊化温度和热焓变化也随之递减,而 RVA 的最高粘度则呈现递增趋势。相关分析发现,甘薯直链淀粉含量与各糊化特性参数间存在一定相关性,但这种相关性的大小又受到品种制约。

The Differential Scanning Calorimetry (DSC) and Rapid Visco-Analyzer (RVA) were used to determine the starch gelatinization characteristics during the growth of three sweetpotato cultivars. The results showed that the starch contents of three sweetpotato cultivars all decreased as growth progressed. Changes of the amylose content at different harvesting periods could be discriminated according to the cultivars. Atthe early harvests amylose contents of Xushu18 and Zheda9201 were relatively high, but those of Zhe3449 were low.As the growth duration prolonged, the peaks of DSC thermograms tended to occur at a low temperature and not to be so obtrusive with the increased width of the peak. Obvious decreases in values of onset, peak and conclusion temperatures, as well as enthalpy of phase transitions, were observed as growth time lengthened. The peak viscosities, as determined through RVA, showed a rising tendency as growth progressed. In addition, statistical analysis revealed that there were correlations between the amylose content and gelatinization characteristics to some extent, which were affected by genotypes evidently.