In plant materials, the migration of the analytes through the
pores on the surface of the particles also dictates the pace and effi-
ciency of extraction. Therefore, as expected, a smaller particle will
have a shorter path for the analyte to travel to reach the surface
and hence have a higher extraction efficiency (Mukhopadhyay,
Luthria, & Robbins, 2006). Particle sizes smaller than 65 lm caused
automatic shutdown of the ASE 300 instrument by clogging the
tubing system. For this reason, particle sizes smaller than 65 lm
were not evaluated for subsequent experiments. Particle sizes significantly
influenced the PWE efficiency; both TPC and RSA% increased
as the particle size decreased (Fig 1a). When the particle
size of 65–212 lm was used instead of 56–1400 lm, there were almost
2 and 1.5-fold of increase in TPC and RSA%, respectively. It
may be more efficient to classify the particles of 65–212 lm into finer particles by using more sensitive commercial sieves. A particle
size of 65–212 lm was used in subsequent experiments.