Abstract This work evaluated the effect of grinding and
sieving process of green tea leaves on particle size
distribution and antioxidant activity. Granulometric
classes ranging from 20 μm to 500 μm were studied.
Hydroalcoholic extracts of green tea powders (GTPs)
were analysed for total phenolic, total flavonoid, and
catechin contents. The fraction of 100–180 μm ground
at 6000 rpm showed the maximum catechin content with
33.5 mg/g dry matter (DM) and, the best antioxidant
activity with IC50 values of 0.28 μg/mL and 0.13 μg/mL
using DPPH and ABTS radical scavenging assays, respec-
tively. However, antioxidant properties and catechin con-
tent decreased for particle of sizes less than 50 μm.
Catechin content was higher for those ground at
6000 rpm as compared to at 18,000 rpm. The best
grinding conditions and particle size were 6000 rpm and
100–180 μm.
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