FOOD SCIENCE ›› 2012, Vol. 33 ›› Issue (23): 13-17.

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


  • Received:2012-07-24 Revised:2012-11-18 Online:2012-12-15 Published:2012-12-12

Abstract: 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.

Key words: green tea, super-micro grinding, antioxidant activity, cholesterol-scavenging activity

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