To prepare the extract, the powder (35 g) was mixed with distilled water (350 mL) at 80 C for 30 min with continuous stirring and was centrifuged at 13,200 g for 10 min at 5 C.
The supernatant was filtered twice through filter papers (Whatman N 1, GE Healthcare UK Ltd., Buckinghamshire, UK). Finally, the filtered extract was stored at 20 C before the
preparation of the film and analysis.