该研究系统比较了干热、预糊化、湿热处理后橡子淀粉理化性质和体外消化特性，结果表明：橡子淀粉表面光滑，主要为椭圆形、球形和不规则形状，粒径分布范围为0.42~26.30 μm，糊化温度为76.75 ℃，干热处理使水分子迁移和脱除，未涉及明确的淀粉糊化与回生，对橡子淀粉的颗粒形状、粒径大小、糊化温度和A型晶体结构等理化指标亦无显著影响；预糊化处理、湿热处理改变了原淀粉的颗粒结构和结晶类型，增大了淀粉颗粒尺寸，粒径分布范围为1.26~416.87 μm，淀粉颗粒变为不规则形状，表面粗糙，糊化温度降为50.17 ℃，ΔH、To、Tp、Tc、冻融稳定性显著降低（P<0.05）；橡子淀粉体外消化速率大小顺序为：干热处理>对照组>湿热处理>预糊化处理，抗性淀粉（RS）含量与之相反，预糊化处理RS含量最高，为38.21%，干热处理RS含量最低，为16.15%。本研究为橡子淀粉的深加工提供一定参考依据，有利于高品质橡子淀粉制品的开发。

The physicochemical indices and in vitro digestibility characteristics of acorn starch were systematically compared after exposure to dry heat, pre-gelatinization, and heat-moisture treatments. The results showed that acorn starch has a smooth surface, with mainly an elliptic, spherical, and irregular shape, with a particle size distribution ranging from 0.42 to 26.30 μm and a gelatinization temperature of 76.75 ℃. Dry heat treatment caused the migration and removal of water molecules, which did not obviously involve starch gelatinization and retrogradation, and had no significant effect on the physical and chemical indexes such as particle shape, particle size, gelatinization temperature, and A-type crystalline structure of acorn starch. Pre-gelatinization and heat-moisture treatments changed the particle structure and crystallization type of raw starch, and increased the size of starch particles, with a particle size distribution range of 1.26~416.87 μm; starch particles became irregular in shape with a rough surface when the gelatinization temperature was reduced to 50.17 ℃, and ΔH, To, Tp, Tc, and freeze-thaw stability were decreased significantly (P<0.05). The in vitro digestion rates of acorn starch were in the order of dry heat treatment > control treatment > heat-moisture treatment > pre-gelatinization treatment. On the contrary, the content of resistant starch was the highest in the pre-gelatinization treatment (38.21%) and the lowest in dry heat treatment (16.15%). This study provides a reference for the deep processing of acorn starch, which can guide the development of high-quality acorn starch products.

湖北省科技计划项目（2022BBA088）；湖南省教育厅重点项目（19A470）