Characterisation of cellulose from coffee silverskin

Abstract

Several methods for the isolation and purification of cellulose from coffee silverskin (CS) were investigated using alkaline, hydrogen peroxide (HP), organosolvents, acetic acid, and their combinations. The process and cellulose were characterised by their yield, cellulose content, colour, alkaline resistance (R10), FTIR spectroscopy, X-ray diffractometry, and thermal stability. Whiteness index (WI), R10, crystallinity, thermal stability, yield, and cellulose content of the solids obtained after extraction were dependent on the extraction procedures. Alkaline ethanol-HP-acetic acid protocol resulted in a cellulosic sample with the highest thermal stability (13% weight loss (WL) in the temperature range of 280–360 °C) and a cellulose Iβ content with 70% crystallinity. These results showed the great potential of CS as a new source of cellulose.