Abstract:This study took the full use of the coffee bean dregs after water extraction using chlorogenic acid，made high value-added mannan-oligosaccharides（MOS）using enzymatic preparation method and analyzed its composition.Coffee bean dregs were hydrolyzed by enzyme to mannan oligosaccharides usig two market-available beta mannase from different sources：enzyme A from Bacillus subtilis，enzyme B from Aspergillus niger.The optimum process conditions（the optium enzyme amount，hydrolysis temperature，pH and enzymolysis time）were obtained through single-factor and orthogonal experiments.The yield of MOS prepared was（52.76±0.11）%by enzyme A and（61.01 ± 0.12）%by enzyme B.The average degree of polymerization（DP）of enzymatic hydrolysate treated with enzyme A and B was about 7.52 and 7.46 respectively.The hydrolysate solution treated with enzyme B was derivative reacted with 1-phenyl-3-methyl-5-pyrazolone（PMP）before liquid chromatography（HPLC）analysis.The composition of mannan oligosaccharides was determined：galactose 42.78%，mannose 42.58%，Arabia sugar 14.64%.The DP of 7.46 satisfied the requirements for preparing functional oligosaccharides.The content of manoligosaccharides was highest，satisfing the requirement that the functional oligosaccharides should be manoligosaccharides.This study will provide technical support for making high value added products from coffee bean dregs.