Comparative evaluation of xylan extraction methods and product characterization from sugarcane bagasse

Abstract

Sugarcane bagasse is a rich source for Hemicelluloses. Xylan is a major type of hemicellulose represented as glucurono- arabinoxylans (GAX) in sugarcane. In the present study, comparative analysis of different xylan extraction methods namely sodium borohydride treatment, dimethyl sulfoxide (DMSO) extraction; dilute acid treatment, sonication, hydrogen peroxide and hot water treatment methods have been carried out for extraction and purification xylan from the bagasse of sugarcane genotypes Co 86032, Co 2001 -15, SES 159, and SES 18. The results showed that alkaline extracted sugarcane bagasse yielded significantly highest xylan yield and recovery in the range of 23.85-32.35% and 72.37%-97% respectively as compared to the rest of the pretreatment methods. Moderate xylan yield (7.68-17.43%) and recovery (22.49-52.89%) was observed using hot water, sodium borohydride and hydrogen peroxide pretreatment methods with significantly highest xylan recovery of 52.89% in hydrogen peroxide pretretated bagasse. Among all the pretreatment methods studied, DMSO, dilute acid and sonication pretreated bagasse samples yielded significantly very low xylan recovery in the range of 1.21-4.89%. Fourier Transmission Infra-Red (FT-IR) spectroscopic analysis of alkali extracted xylan showed similar spectral profile of commercial Beechwood xylan and indicated the presence of hemicellulose structures. These results evidenced the simple economically feasible xylan extraction technology and provided much more scope for using sugarcane bagasse as potential xylan source to produce industrially important value added products.

Keywords

• hemicellulose; xylan; sugarcane bagasse; pretreatment; value added product