DOI: https://doi.org/10.55373/mjchem.v26i5.338

Keywords: Microcrystalline cellulose; acid hydrolysis; trifluoroacetic acid

Abstract

Pineapple leaves and crowns (PLC) have high cellulose contents of 74.50% and 51.20%, respectively, positioning them as promising sources to produce microcrystalline cellulose (MCC). This study examines the effect of hydrolysis time and acid concentration on MCC yield and crystallinity. Trifluoroacetic acid (TFA) was utilised in the acid hydrolysis process, applied at concentrations of 40% (v/v) and 65% (v/v) at 45 min and 90 min, respectively. The produced MCC is distinguished by its morphology, yield, crystallinity index, and functional groups. The highest yield of dried MCC produced from 2 g of PLC was 16.25% at a process condition of 40% (v/v) for 90 min, whereas the highest crystallinity index was obtained at 67.79% for hydrolysis at 65% (v/v) of TFA at 90 min. An irregular rod-like structure and inconsistent diameter of the obtained MCC showcases notable physical properties. This study expected the presence of carbonyl groups on the surface of MCC; however, due to insufficient energy for esterification at low temperatures, the carbonyl group was absent on the surface of MCC samples, as indicated in the FTIR spectra. This study offers a potential technique for investigating the use of TFA as a sole material in both pre-treatment and hydrolysis steps, which could simplify the extraction process.