物理粉碎方法及粒径对绿茶微粉的体外抗氧化和清除胆固醇作用的影响

Effects of Physical Grinding Methods and Particle Size on in vitro Antioxidant and Cholesterol-Scavenging Activity of Super-micro Green Tea Powder

研究绿茶超微物理粉碎方法及粒径对超微绿茶体外抗氧化及吸附胆固醇活性的影响。以普通绿茶和富硒绿茶为原料,采用气流粉碎、行星式球磨粉碎和振动磨粉碎3种方法制备超微绿茶,使用激光粒度分析仪和扫描电镜分析其粒径分布和形态。在此基础上,分别考察粒径对茶粉DPPH自由基清除能力和胆固醇吸附能力的影响。行星式球磨粉碎制备的超微茶粉粒径最小,其中值粒径(D50值)分别为超微富硒绿茶3.398μm和超微普通绿茶3.462μm,超微茶粉粒子呈现分布均匀的不规则碎片。超微普通绿茶比普通绿茶具有显著的DPPH自由基清除能力,超微富硒绿茶比普通富硒绿茶表现出更强的吸附胆固醇能力。超微粉碎可显著提高绿茶体外抗氧化和吸附胆固醇活性。

This study aimed to investigate the effects of physical grinding methods（airstream pulverization,planetary ball milling and vibration milling） and particle size on in vitro antioxidant（DPPH free radical scavenging activity） and cholesterol-scavenging activity of super-micro green tea powder.Super-micro powder samples of ordinary（SOGT） and Se-rich（SSGT） green tea were prepared by different physical grinding methods and examined for particle size distribution and morphology using a laser particle analyzer and a scanning electron microscope.Planetary ball milling provided minimum particle size of green tea powder and a median particle size（D50） of 3.398 μm and 3.462 μm for SOGT and SSGT,respectively.In addition,tea powder samples showed a uniform particle size distribution but an irregular shape.SSGT had higher DPPH radical scavenging activity but weaker cholesterol-scavenging activity than SSGT.