以芸豆为原料，分离内含淀粉的完整芸豆子叶细胞，在120、140、160、180 ℃下干热处理4 h。通过X射线衍射和热分析其淀粉结晶结构，并基于一级动力学模型分析其消化动力学。结果表明：与相同处理条件下的芸豆淀粉相比，芸豆子叶细胞表皮皱缩，体积略有减小，形态趋于球形，偏光十字略有减弱。芸豆子叶细胞的结晶度有所下降，X衍射图仍为C型，原子叶细胞的起始糊化温度和糊化焓降低约0.41 ℃和4.61 J/g，在140 ℃干热处理条件下，子叶细胞的起始糊化温度和糊化焓降低了0.73 ℃和11.70 J/g。在消化性上，180 ℃处理下的芸豆子叶细胞与未经热处理的细胞相比，消化程度增加了约3.02%。但芸豆子叶细胞在360 min的水解率（~8%）均显著低于芸豆淀粉（~60%），可能是由于α-淀粉酶进入芸豆子叶细胞，细胞内蛋白质组分对淀粉颗粒形成包裹屏障，从而阻碍了淀粉酶与细胞内淀粉的结合，导致了芸豆子叶细胞较慢的体外淀粉消化速率。本研究表明采用120 ℃~180 ℃干热条件处理芸豆子叶细胞，是一种较优的加工方式，可获得低血糖生成指数的芸豆产品。

The intact cotyledon cells were isolated from pinto beans and treated with dry heat at 120, 140, 160, 180 ℃ for 4 h. The crystalline structures of starch were analyzed by X-ray diffraction and differential scanning calorimeter, and the digestion kinetics were analyzed based on the first-order kinetic model.The results showed that compared with the pinto bean starch under the same heating treatment condition, the pinto bean cotyledon cell epidermis shrank, the volume decreased slightly, the shape tended to be spherical, and the polarized cross weakened slightly. The crystallinity of the pinto bean cotyledon cells decreased, but the X-ray diffraction patterns remained to be C type. The initial gelatinization temperature and enthalpy of gelatinization decreased by 0.41 ℃ and 4.61 J/g, respectively. In terms of digestibility, the digestion extent of pinto bean cotyledon cells treated at 180 ℃ was increased by 3.02% than that of untreated pinto bean cotyledon cells. However, the hydrolysis rate of cells at 360 min (~8%) was significantly lower than that of pinto bean starch (~60%), which might be due to starch granules were wrapped by the protein components in the cells that hinder the binding of α-amylase to intracellular starch, which leads to slow digestion rate of starch in pinto bean cotyledon cells in vitro.The results showed that the dry heat treatment of pinto bean cotyledon cells at 120 ℃~180 ℃ was an excellent processing method and the product with lowglycemic index could be obtained.

国家自然科学基金项目（31701546），广东省自然科学基金项目（2017A030313207）