本研究以水芹为材料，通过与传统粗粉碎相对比，研究了超微粉碎时间对水芹粉末的粒度分布、形貌特征、膳食纤维、黄酮及总酚总溶出量、颜色、功能特性以及流动性的影响。进一步针对不同粒度的水芹粉末中主要活性成分的溶出特性，进行测定并对比分析。最后，采用DPPH自由基清除率、羟基自由基清除率、ABTS自由基清除率、总还原力及氧自由基吸收能力（ORAC），评价了水芹粉末的抗氧化活性。结果表明：随着超微粉碎时间的延长，水芹粉末粒径降低至42.19 μm，比表面积增加至0.28 m2/g，可溶性膳食纤维溶出量增加至7.26%，黄酮和总酚溶出量显著提高。同时，超微粉碎处理增强了水芹粉的亮度和绿度，改善其溶解性、持水力及膨胀力，但使得水芹超微粉的流动性略微降低。此外，超微粉碎处理极大地提高了黄酮、总酚、可溶性蛋白及多糖的溶出速率，且提高了水芹粉末对DPPH、羟基、ABTS自由基清除能力、总还原力及氧自由基吸收能力。

In this paper, using water dropwort as material, the effects of superfine grinding time on the particle size distribution, morphology, the dissolutions of dietary fiber, flavonoids, total polyphenols, and color, functional and flow properties of water dropwort powder were investigated by comparing with the traditional coarse grinding. Moreover, the dissolution characteristics of phytochemicals in water dropwort powder with different particle sizes were measured and compared. Then, the DPPH radical scavenging activity, hydroxyl radical scavenging activity, ABTS radical scavenging activity, total reducing power and oxygen radical absorbance capacity (ORAC) assays were evaluated. The results showed that with the prolongation of superfine grinding time, the particle size of water dropwort powder decreased to 42.19 μm, the specific surface area increased to 0.28 m2/g, the dissolution of soluble dietary fiber increased to 7.26%, and the dissolutions of flavonoids and total polyphenols obviously increased. Meanwhile, superfine grinding enhanced the brightness and greenness, improved its solubility, water holding capacity and swelling capacity, but slightly reduced its fluidity. In addition, superfine grinding greatly improved the dissolution rate of flavonoids, total polyphenols, soluble proteins and polysaccharides, and also enhanced the DPPH, hydroxyl, ABTS radical scavenging activity, total reducing power, and oxygen radical absorbance capacity.

安徽省科技重大专项项目（16030701073）；国家自然科学基金项目（31771974）