. Preparation of microfibrillated cellulose
Microfibrillated cellulose (MFC) was prepared according to a previously described protocol (Winuprasith & Suphantharika, 2013). Briefly, dried mangosteen rind was ground to pass through a 100 mesh sieve. The resulting mangosteen rind powder was extracted for cellulose using hot (90 °C) aqueous NaOH solution at pH 12, washed, neutralized, and then bleached using hot H2O2 solution. The yellow-brown, water swollen purified cellulose was collected by filtration. The purified cellulose was used for the preparation of MFC by re-dispersing in distilled water at a concentration of 1% w/w and then passing through a high pressure homogenizer (type Panda, Niro-Soavi S.p.A, Parma, Italy) at a pressure of 500 bar for 20 passes at room temperature (25 °C). The resulting material was yellow-brown gel-like aqueous matter, having an MFC concentration of 1% w/w and exhibiting neither flocculate nor sediment when diluted with water.