Extraction of hemicellulose from corn cob and sugarcane bagasse and its application

Abstract

Agricultural residues like corn cob and sugarcane bagasse have high amount of hemicellulose i.e. ~20-36%, and can be utilized for the production of xylooligosaccharides and bio-films. This thesis is focused on development of efficient protocol for the extraction of hemicellulose with high yield from corn cob and sugarcane bagasse and further transforming them into xylooligosaccharides and bio-films. Hemicelluloses were isolated using NaOH, NH4OH and combination of both at different concentrations and temperatures. The modified alkaline protocol (NaOH + NH4OH) utilized for extraction of hemicellulose from corn cob and sugarcane bagasse resulted in achieving high amount of hemicellulose than individual NaOH and NH4OH protocols with high purity. 2D-HSQC NMR study indicated that hemicellulose extracted from corn cob is made up of (1and#8594;4)-linked and#946;-D-Xylp units with small amount of and#945;-L-Araf residues and the hemicellulose extracted from sugarcane bagasse contained a backbone of (1and#8594;4)- linked and#946;-D-Xylp units with and#945;-L-Araf residues and (1and#8594;4)-linked and#945;D-glucan. Further, at optimized conditions i.e. 0.25 M H2SO4 at 100 °C and 60 min, the maximum production of xylooligosaccharide from corn cob (69%) and sugarcane bagasse (13%) were achieved. Further, bio-films were prepared from hemicellulose extracted from corn cob and sugarcane bagasse through different alkaline protocols and their mechanical properties were studied. Films prepared from hemicellulose extracted from corn cob and sugarcane bagasse using mixed alkaline protocol achieved the maximum tensile strength of 16.3MPa and 17.3 MPa respectively, without addition of sorbitol. It is anticipated that the findings of this research will be beneficial for extracting hemicellulose and further production of xylooligosaccharides and bio-films. newline