Hydrogen peroxide pretreatment efficiently assisting enzymatic hydrolysis of chitosan at high concentration for chitooligosaccharides. (June 2019)

• Record Type: Journal Article
• Authors: Li, Meng; Han, Jiang; Xue, Yong; Dai, Yanfei; Liu, Jian; Gan, Lihui; Xie, Rusheng; Long, Minnan
• Is Part Of: Polymer degradation and stability. Volume 164(2019)
• Page Start: 177
• Page End: 186
• Publication Date: 2019-06
• Subjects: Chitooligosaccharides -- Oxidation pretreatment -- Fed-batch -- Cellulase -- High concentration; LMWC Low Molecular Weight Chitosan -- COSs Chitooligosaccharides -- DP Degree of Polymerization -- DD Degree of Deacetylation -- TLC Thin Layer Chromatography -- Mv Viscosity Average Molecular Weight -- Mw Weight Average Molecular Weight -- Mn Number Average Molecular Weight -- SED Substrate Enzymatic Digestibility; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2019.04.011
• Languages: English
• ISSNs: 0141-3910

Abstract

Abstract: Chitooligosaccharides (COSs) have continuously attracted considerable attention as numerous biological activities. The highly efficient preparation of COSs, however, is still a challenge. In this paper, a clean two-stage method is developed to hydrolyze chitosan at high concentration into COSs, comprising of pretreatment with hydrogen peroxide (H2 O2 ) and hydrolysis with food-grade cellulase. The pretreatment reduced the viscosity of chitosan solution quickly, making more chitosan dissolving. Chitosan solution at high concentration (9%, w/v) was successfully prepared by fed-batch chitosan during the oxidative pretreatment. Within 6 h, the chitosan was enzymatically hydrolyzed to oligosaccharides with degree of polymerization (DP) of 2–9 and a small amount of monosaccharide, which was analyzed by thin layer chromatography (TLC) and MALDI-TOF MS. In addition, the results from FT-IR and NMR spectra demonstrated the chemical structure of degraded chitosan was not significantly altered. In summary, the two-stage method shows great potential in large-scale production of COSs. Besides, it is expected to couple with membrane bioreactor and immobilized enzyme technology to realize production of COSs with controlled molecular weight. Highlights: A quick preparation technology of high concentration of chitosan solution was developed. A two-stage method was established to product chitooligosaccharides from high-concentration chitosan. Chitooligosaccharides with degree of polymerization 2–9 was obtained in 6 h. The two-stage method is green and cost-effective.