Microwave-assisted alkali extraction of bagasse hemicellulose enhanced by an enzymatic pretreatment process

Extraction of hemicelluloses is a primary step in the conversion of plant biomass to valuable biofuels and chemicals. Hemicellulose is distributed in the fiber cell wall, and the compact structure of the fiber cell wall barricades the transport of hemicelluloses in the extraction process. In this paper we presented a novel microwave-assisted extraction process enhanced with an enzymatic pretreatment to improve the hemicelluloses extraction rate from bagasse. Experimental results showed that the enzyme dosage, alkali concentration and microwave irradiation time were main factors governing the yield of hemicellulose. The optimal conditions of the enzymatic pretreatment were: enzyme dosage of 138 IU/g bagasse and irradiation time of 30 min. Under these conditions, 86% of the hemicellulose in bagasse was extracted. After the enzymatic pretreatment the surface area of bagasse increased significantly which facilitated the subsequent microwave-assisted extraction process.