Abstract:To realize the efficient preparation and utilization of jujube polysaccharides, a deep eutectic solvent (DES)-based ultrahigh pressure extraction technique was established, and the antioxidative activity of the polysaccharides was investigated. Seven different types of DES systems were tested for their effectiveness in extracting polysaccharides from pretreated jujube powder. Based on single-factor tests, the Box-Behnken central composite design was used to optimize the extraction process. According to the results, the optimal DES system for extracting jujube polysaccharides consisted of choline chloride and ethylene glycol. The four-factor regression model established in this study determined the optimal extraction conditions to be as follows: extraction pressure, 483 MPa; duration, 8.25 min at a constant temperature; molar ratio of choline chloride to ethylene glycol, 1:3.75; and water content of the DES system, 53%. Under these conditions, the actual extraction yield of jujube polysaccharides was 14.22%. The obtained polysaccharides exhibited high antioxidative activity, with a DPPH radical scavenging activity of 1.47 mg AA/g DW, an ABTS radical scavenging activity of 10.69 mg AA/g DW, a FRAP value of 30.43 μmol FeE/g DW, and an ORAC value of 193.67 μmol TE/g DW. The results showed that the DES based ultrahigh pressure extraction process has the potential to realize the high-yielding production of jujube polysaccharides with excellent antioxidative activity.
