Extraction and preliminary purification of polysaccharides from Camellia oleifera Abel. seed cake using a thermoseparating aqueous two-phase system based on EOPO copolymer and deep eutectic solvents

•EOPO/DES ATPS was first developed for the extraction of polysaccharides from C. seed cake.•Thermoseparating ATPS was used for the preliminary purification of polysaccharides.•Polysaccharides and EOPO can be recovered by temperature-induced phase separation.•The antioxidant activity of DES-P was better than that of Water-P. A thermoseparating aqueous two-phase system (ATPS) based on ethylene oxide-propylene oxide (EOPO) copolymer and deep eutectic solvents (DES) was developed for the extraction and preliminary purification of polysaccharides in Camellia oleifera Abel. seed cake. DESs were used as the extraction media for obtaining the crude extract. The maximum extraction yield (Y) of polysaccharides was 152.37 mg/g in the crude extract. Then the crude polysaccharides were extracted and preliminary purified by EOPO/DES ATPS. The maximum extraction efficiency (E.E.) of polysaccharides was 86.91% in EOPO-rich phase by the first ATPS extraction. The EOPO-rich phase was separated and the polysaccharides were recovered by temperature-induced phase separation. The maximum recovery efficiency (R.E.) was 84.92% in aqueous phase by the second ATPS extraction. This thermoseparating ATPS possesses the merits of good environment-friendlies, simple operation, and easy recovery of components, which can be used as an efficient method for the extraction and separation of polysaccharides.