optimization of green extraction of polysaccharides and antioxidants from purgative manna using deep eutectic solvents and ultrasonic-assisted technique

In this work, the ultrasonic technique is combined with deep eutectic solvent (des) was used as a green method for the extraction of polysaccharides and antioxidants from a rarely studied manna, purgative manna (shirkhesht). between twenty solvents, maximum values of total carbohydrate content (tcc) and total phenolic content (tpc) were obtained for choline chloride-lactic acid. response surface methodology (rsm) and the box-behnken design were used for the optimization of ultrasonic-assisted extraction. optimal values of experimental parameters to achieve the highest total carbohydrate content (7.62 mg glucose/gram of dry weight), total phenolic content (3.45 mg gallic acid equivalent/gram of dry weight), and yield (77.7%) were obtained at the liquid-to-solid ratio (l/s) of 100 ml/g, temperature of 30 ◦c, time of 20 min, and water content in des (wc%) of 10% v/v. arabinose, xylose, mannose, glucose, and galactose were found in extracted polysaccharides with molar ratios of 1.00:1.21:0.83:4.09:2.35. six assays for antioxidant capacity and four extraction methods (ultrasonic, microwave, maceration, and soxhlet) were compared, and ultrasonic extraction had the best performance. selected des solvents (choline chloride-lactic acid) were compared with conventional solvents such as methanol, ethanol, acetone, and water. improvement in extraction for this des to conventional solvents was between 70-237%.