2.3. Extraction of crude phenolics of rice fractions
The crude phenolic compounds present in rice fractions were
extracted with 80% aqueous methanol (1:10, w/v) at 25 C with
shaking in an incubator at 150 rpm for 16 h. The mixtures were
centrifuged at 2500 rpm for 20 min and the supernatants were collected.
The residues were re-extracted under the same conditions,
and supernatants from both extractions were combined. The solvent
was removed under vacuum at 40 C and the resulting concentrated
slurries were lyophilised and stored at 20 C pending
analysis.