Thermo-responsive ionic liquids-mediated extraction of Rosa roxburghii Tratt polysaccharides

s Rosa roxburghii Tratt ( R. roxburghii ) polysaccharides have important application value in the fields of food and medicine due to their significant antioxidant and hypoglycemic activities. However, conventional extraction methods have low efficiency and poor environmental friendliness. In this study, a sustainable and highly efficient approach for R. roxburghii Tratt extraction was developed using thermo-responsive ionic liquids (TRILs). The choline chloride/lithium bis(trifluoromethylsulfonyl)imide system exhibited the optimal performance, enabling facile polysaccharide recovery via temperature regulation. It was found that the response temperature of TRIL was between 20 and 80 °C. The optimized extraction process achieved a maximum polysaccharide yield of 212.0 mg/g. Changing the temperature can change the hydrophilicity and hydrophobicity of TRIL, leading to the enrichment of polysaccharides in the aqueous phase and the recovery of polysaccharides. Additionally, this TRIL displayed excellent reusability, retaining an extraction capacity of 195.0 mg/g (retention rate 91.9 %) after five cycles. Subsequent purification yielded three polysaccharide fractions (RTFP-T1, RTFP-T2, and RTFP-T3). RTFP-T3 displayed superior antioxidant activity, scavenging 97.13 % of ABTS and 79.79 % of DPPH radicals. This study not only provides innovative solutions for the sustainable extraction of Rosa roxburghii Tratt polysaccharides, but also lays the technical foundation for the industrial application of natural active polysaccharides.