Lin Ek Kai, Wang Shujun, Brand-Miller Jennie, Copeland Les
Department of Plant and Food Sciences, Faculty of Agriculture and Environment, The University of Sydney, NSW 2006, Australia.
Food Funct. 2014 Oct;5(10):2509-15. doi: 10.1039/c4fo00354c. Epub 2014 Aug 15.
Potatoes are a popular source of dietary carbohydrate worldwide and are generally considered to be a high glycemic index (GI) food. Potato starch characteristics play a key role in determining their rate of digestion and resulting glycemic response. Starches isolated from seven potato cultivars with different GI values, including a low GI cultivar (Carisma), were examined for relative crystallinity, granule size distribution, amylopectin chain length, and thermal and pasting properties. Starch from the Carisma cultivar was more thermally stable and more resistant to gelatinization, with significantly higher (p < 0.05) pasting temperature and differential scanning calorimetry (DSC) gelatinization onset, peak and conclusion temperatures, compared to the other cultivars. Differences between the potatoes in the other properties measured did not align with the GI ranking. Thermal analysis and starch pasting properties may be useful indicators for preliminary identification of potato cultivars that are digested slowly and have a lower GI.
土豆是全球范围内广受欢迎的膳食碳水化合物来源，通常被认为是高血糖生成指数（GI）的食物。土豆淀粉特性在决定其消化速率和由此产生的血糖反应方面起着关键作用。对从七个具有不同GI值的土豆品种（包括低GI品种Carisma）中分离出的淀粉进行了相对结晶度、颗粒大小分布、支链淀粉链长以及热性能和糊化性能的检测。与其他品种相比，Carisma品种的淀粉热稳定性更高，更耐糊化，其糊化温度以及差示扫描量热法（DSC）的糊化起始温度、峰值温度和结束温度显著更高（p < 0.05）。所测其他特性方面土豆之间的差异与GI排名不一致。热分析和淀粉糊化性能可能是初步鉴定消化缓慢且GI较低的土豆品种的有用指标。
