The effect of extrusion feed moisture (FM) on the microstructure, pasting, physico-functional properties and in vitro starch digestibility (IVSD) of corn and potato starches was investigated using scanning electron microscopy (SEM), X-ray diffractometry and a rapid visco-analyser. Starches were extruded at 14, 18 and 22% FM with an extrusion temperature of 100 °C and a screw speed of 100 rpm. Extruded starches showed lower L* (lightness) values and higher a* and b* values than native starches. An increase in FM increased the L* values and decreased the a* and b* values of extruded starches. Extrusion resulted in complete destruction and reduced crystallinity of the starch structure. Extruded starches showed a lower water absorption index (WAI), peak viscosity (PV), final viscosity (FV), breakdown viscosity (BDV) and setback viscosity (SBV) with a higher water solubility index (WSI) and IVSD than native starches. FM showed a negative correlation with the WSI and IVSD and a positive correlation with the WAI, PV, FV, BDV and SBV of extruded starches.

中文翻译：

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饲料水分对双螺杆挤压玉米和马铃薯淀粉的微观结构、结晶度、糊化、物理功能特性和体外消化率的影响

使用扫描电子显微镜 (SEM)、X 射线衍射仪和快速粘度计研究了挤压饲料水分 (FM) 对玉米和马铃薯淀粉的微观结构、糊化、物理功能特性和体外淀粉消化率 (IVSD) 的影响。 - 分析仪。淀粉以 14%、18% 和 22% FM 挤出，挤出温度为 100 °C，螺杆速度为 100 rpm。与天然淀粉相比，挤出淀粉显示出更低的 L*（亮度）值和更高的 a* 和 b* 值。FM 的增加增加了 L* 值并降低了挤出淀粉的 a* 和 b* 值。挤出导致淀粉结构的完全破坏和结晶度降低。挤出淀粉显示出较低的吸水指数 (WAI)、峰值粘度 (PV)、最终粘度 (FV)、分解粘度 (BDV) 和回缩粘度 (SBV) 具有比天然淀粉更高的水溶性指数 (WSI) 和 IVSD。FM与WSI和IVSD呈负相关，与挤出淀粉的WAI、PV、FV、BDV和SBV呈正相关。