Abstract: 【Objective】On the basis of dynamic trend of separating and purifying of fermented apple pomace polysaccharides, the authors further investigated the structural properties , and in hoping of further elucidating the separating, purifying, bioactivity and processing properties of fermented apple pomace polysaccharides.【Method】Apple pomace polysaccharides (AP), wine fermented apple pomace polysaccharides (WFP) and vinegar fermented apple pomace polysaccharides (VFP) were used as experimental materials. On the basis of analysis of polysaccharides content, the authors used DEAE-52 cellulose column, NaCl as eluent, to separate polysaccharides according to the polarity difference among polysaccharides components. Through collecting effluent liquid using fraction collector and then the polysaccharides content was determined using with phenol sulfuric acid method, and the elution curve was depicted. Meanwhile, the obtained polysaccharides components with DEAE-52 cellulose column were further separated using Sephadex G-200 gel column, distilled water as eluent. After obtaining the separated polysaccharides components, the structural properties were thoroughly analyzed by using X-ray powder diffraction to observe the crystallographic structure, Thermogravimetric Analyzer was used to analyze thermogravimetric characteristics, Laser particle size analyzer to analyze granularity, and Congo red was used to explore triple helix structure of polysaccharides. Finally, Desktop Scanning Electron Microscope was also used to observe and analyze micro-structure of apple pomace polysaccharides.【Result】The content of original apple pomace polysaccharides was approximately 70%. Because the polysaccharides didn’t include protein and nucleic acid, so the extraction efficiency was excellent. NAP0.1 and NAP0.2 were obtained after AP were purified firstly through DEAE-52 cellulose column and 0.1, 0.2 mol·L^-1 NaCl were respectively used as eluents and then through Sephadex G-200 gel column and distilled water as eluent. Meanwhile, NWFP0, NWFP0.1 and NWFP0.2 were obtained after WFP was purified with DEAE-52 cellulose column and subsequently Sephadex G-200 gel column. After VFP was separated, NVFP0, NVFP0.1 and NVFP0.2 were obtained, too. All the separated constituents included over 92% polysaccharides, suggesting separation effect was satisfactory. Three polysaccharides, AP, WFP and VFP, were non-crystalline material between before and after separation. Concentration temperature of polysaccharides was strictly limited below 65℃, and the processing temperature was below 150℃. Before separation, AP, WFP and VFP all had triple helix structure. After separation, triple helix structure still existed in NWFP0, NVFP0, and NVFP0.1, while NAP0.1 and NAP0.2 had no triple helix structure. Compared with the original apple pomace polysaccharides, the separated apple pomace polysaccharides had better stability and smaller particle size, because lower dispersion coefficient of particle size was observed. Besides, flake structure in polysaccharides was less, and cross-linking effect attenuated after separation, which is beneficial for development of polysaccharides bioactivity.【Conclusion】Fermented apple pomace included over 70% polysaccharides, and polysaccharides content was up to 92% after crude polysaccharides was separated and purified. Besides, according to XRD, TG, LPSA and Congo red as well as DSEM analysis, it was concluded that the changes of solubility, viscosity and physical characteristics facilitated separated apple pomace polysaccharides developing bioactivity and processing characteristics.

Key words: fermentation, apple pomace, polysaccharides, separation and purification, structure Characterization, processing characteristics