Isolation and Characterization of Microcrystalline Cellulose from Eragrostesis Teff Straw

Abstract

AbstractIn this work, microcrystalline cellulose was isolated from Eragrostis teff straw through a chemical method using acidified sodium chlorite, alkali treatment, and acid hydrolysis and successively, various characterizations were conducted using different techniques. The ash, volatile matter, moisture, and fixed carbon contents were calculated and found to be 5.1%, 74.2%, 8.4%, and 15.6%, respectively. The extractives, lignin, hemicellulose, and cellulose content were found to be 6.4%, 15.6%, 29.5%, and 37.5%, respectively. The yield of the microcrystalline cellulose (MCC) extracted was 70.8% and the particle size was 156.4 μm. The pH, loss on drying, moisture sorption capacity, water-soluble substance, and hydration capacity of extracted MCC were found to be 6.7, 4.6%, 18.6%, 0.18%, and 3.7, respectively. The Fourier transformed infrared spectroscopy (FTIR) result of microcrystalline cellulose shows the removal of pectin, waxes, and lignin. The X-ray diffraction result shows that the crystallinity (CI%) of teff straw and microcrystalline cellulose was 47.7% and 72.8% respectively which reveals the removal and reduction of amorphous parts in the straw. A result of thermogravimetry analysis and differential thermogravimetry analysis (TGA/DTGA) reveals that microcrystalline cellulose shows better thermal stability over the untreated straw. The onset temperature of the straw was 255 ℃ and the maximum degradation temperature was 354 ℃ while the onset temperature for extracted microcrystalline cellulose was 315 ℃ and maximum degradation temperature was 363 ℃. KeywordsMicrocrystalline celluloseAlkali treatmentAcid hydrolysis