Characterization of physicochemical properties and antioxidant activity of polysaccharides from shoot residues of bamboo (Chimonobambusa quadrangularis): Effect of drying procedures

In the present study, the bamboo shoot (Chimonobambusa quadrangularis) residue (BSR)-derived polysaccharides (CPS) were dried using different drying procedures, including hot air-, vacuum-, freeze-, and spray-drying. The influences of different drying procedures on the chemical compositions, physicochemical characteristics, and antioxidant activity of CPS were investigated. The results indicate that freeze-dried CPS possessed the highest polysaccharide yield (8.86%) and uronic acid content (9.42%), and the lowest medium-high molecular weight (117.49 kDa) and glucose content (5.81 mol%). Also, freeze-dried CPS had better water (5.17 g/g) and oil retention capacities (2.32 g/g) than hot air- and vacuum-dried CPS. Moreover, freeze-dried CPS exhibited the most potent antioxidant ability. Based on correlation analysis, a higher uronic acid content, lower molecular weight and lower glucose content might be closely associated with the better antioxidant activity of the freeze-dried CPS. Hence, the above results revealed freeze-drying was the optimal method for industrial production of high quality CPS.