High-efficiency separation of hemicellulose from bamboo by one-step freeze-thaw-assisted alkali treatment

The selectivity of alkali treatment (AT) for hemicellulose separation is reduced due to the alkali solubility of lignin. It was improved using freeze-thaw-assisted alkaline treatment (FT/AT). In this study, bamboo hemicel-lulose was separated via a one-step freeze-thaw-assisted alkali treatment (OFT/AT). The effects of freezing temperature, freezing time, alkali concentration, and treatment time on bamboo components were studied. The separation yield of hemicellulose was 73.26%, compared to 64.00% using conventional FT/AT. The separation of lignin and cellulose was inhibited as alkali concentration decreased from 7.0% to 5.0%. The extraction yield of hemicellulose increased from 46.35% to 56.12%. Structural analysis of extracted hemicellulose revealed the effective inhibition of the breakage of the xylose backbone and arabinose side chain of hemicellulose. This indicated that the molecular structure of extracted hemicellulose was relatively complete. It provides theoretical support for the efficient separation of hemicellulose by AT.

Automated summary

In this study, the separation of bamboo hemicellulose was successfully achieved via a one-step freeze-thaw-assisted alkali treatment (OFT/AT). The selectivity of hemicellulose separation was improved, leading to a higher separation yield compared to conventional freeze-thaw-assisted alkaline treatment (FT/AT). The inhibition of lignin and cellulose separation was observed as the alkali concentration decreased, while the extraction yield of hemicellulose increased. Structural analysis revealed that the extracted hemicellulose had a relatively complete molecular structure, providing theoretical support for efficient hemicellulose separation by alkali treatment.