Process optimization and structural characterization of Chuanminshen violaceum polysaccharides extracted by deep eutectic solvents

LI Yaxin; LUO Min; LIU Yuanfu; SUN Quanjiao; HUANG Junming; WEN Jianxia; DU Wenya; ZHANG Liang

doi:10.12187/2026.01.005

Abstract：[Objective]This study aims to explore and optimize a green and efficient extraction technology for Chuanminshen violaceum polysaccharide(CVP)and promote its development and utilization in the field of functional foods.[Methods]A deep eutectic solvents(DES)-based extraction method for CVP was established and optimized via single-factor experiments and response surface methodology.Subsequently,the extracted CVP was purified by ion-exchange chromatography column and gel filtration chromatography column,respectively.The structure of CVP was characterized by combining ion chromatography,high-performance gel permeation chromatography,infrared spectroscopy,and scanning electron microscopy.[Results]The optimal extraction conditions were determined as follows:choline chloride-citric acid DES system(with a molar ratio of 1∶1 and a water content of 30%),liquid-to-solid ratio of 20∶1,extraction temperature of 70℃,and extraction time of 120 min.Under these conditions,the extraction rate of CVP was(44.17±0.19)%,an increase of more than 26%over the traditional extraction method;After purification,two CVP fractions(CVP-1-1 and CVP-2-1)with single relative molecular weight and homogeneous structure were obtained.Among them,CVP-1-1 was composed of glucose and galactose,with a total sugar content of(94.87±0.80)%and a relative molecular weight of 9471 Da;CVP-2-1 was composed of glucose,galactose and rhamnose,with a total sugar content of(92.01±1.77)%and a relative molecular weight of 18 159 Da;Both fractions were pyranose ring polysaccharides containing α-glycosidic bonds and β-glycosidic bonds.Their micro-morphologies were related to relative molecular weight and purification process;the purified polysaccharides exhibited a more porous and loose surface,a higher degree of fragmentation,and differed in relative molecular weight,as well as the degree of fragmentation and aggregation.[Conclusion]Applying DES to CVP extraction,the extraction rate is significantly increased compared with the traditional extraction method.Moreover,the obtained CVP has a lower relative molecular weight,which may have high antioxidant activity,providing a reference for the development of CVP-based functional foods.