本研究分离出完整芸豆子叶细胞作为全食品的模型，并以芸豆淀粉为对照，研究了常压蒸煮、高压蒸煮、高温焙烤和油炸这4种热处理方式对细胞的颗粒形貌，结晶结构及体外消化动力学的影响。结果表明：高压和常压蒸煮后，芸豆细胞偏光十字显著减弱，结晶度降低约12%，无法检测到糊化峰；然而芸豆淀粉经高压和常压蒸煮后，颗粒结构被破坏，偏光十字消失。芸豆细胞和淀粉经油炸和高温焙烤处理后，颗粒形貌无显著性差异，但糊化焓和相对结晶度显著降低。经不同热加工处理条件下芸豆子叶细胞的消化率依次为：高压蒸煮（89.45%，0.0132 min-1）>常压蒸煮（47.77%，0.0033 min-1）>高温焙烤（3.15%，0.0001 min-1）≈油炸（2.31%，0.0003 min-1）≈未处理（1.80%，0.0001 min-1）。不论何种热加工方式，芸豆细胞的表观消化速率和消化程度远小于相同热处理后的淀粉。这可能是由于细胞壁和蛋白质等物质对消化酶的吸附及物理屏障作用。本研究表明采用高温焙烤和油炸的热处理方式可获得低血糖生成指数的芸豆产品。

In this paper, intact cotyledon cells isolated from pinto bean were used as a whole food model and kidney bean starch was used as the control, the effects of four heat processing methods (normal-pressure cooking/boiling, high-pressure cooking/autoclaving, high-temperature baking and deep frying with oil) on the particle morphology, crystalline structure and in vitro digestion kinetics of starch in intact pinto bean cells were studied. The results showed that after high-pressure and normal-pressure cooking, the birefringence polarization cross of pinto bean cells was significantly weakened, the crystallinity decreased by about 12%, and the gelatinization peak could not be detected. However, high-pressure and normal-pressure cooking destroyed the granular structure of pinto bean starch and caused the disappearance of the birefringence polarization cross. The deep frying and high-temperature baking did not change significantly the morphology of pinto bean cells and starch but decreased the enthalpy of gelatinization and relative crystallinity. The digestion rate of pinto bean cells with/without different heat treatments decreased in this order: high-pressure cooking (89.45%, 0.0132 min-1) > normal-pressure cooking (47.77%, 0.0033 min-1) >high-temperature baking (3.15%, 0.0001 min-1) ≈ deep frying (2.31%, 0.0003 min-1) ≈ untreated (1.80%, 0.0001 min-1). Regardless of the thermal processing methods, the apparent digestion rate and degree of digestion of pinto bean cells were much lower than those of the starch subjected to the same heat treatment, possibly due to the adsorption of digestive enzymes and physical barrier effect of substances such as cell walls and intracellular proteins. The research results indicate that low GI pinto bean products can be obtained by high-temperature baking and deep frying with oil.

中新国际联合研究院-湖南汇富康达项目资助（201-D119002）