Comparison of different extraction methods for polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products

The aim of this study was to evaluate the influences of extraction methods on the yield, chemical structure and antioxidant activity of polysaccharides from bamboo shoots (Chimonobambusa quadrangularis) processing by-products (CPS). CPSs were extracted by using five methods including hot water extraction (HWE), accelerated solvent extraction (ASE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE). The experimental results showed that the uronic acid contents, monosaccharide contents, molecular weights and antioxidant activities of the five CPSs were significantly different. CPS extracted using ASE method (ASE-CPS) possessed the highest extraction yield (9.94%), the highest medium-high-molecular-weight value (136.07 kDa) and notable antioxidant ability. UAE-CPS had the highest uronic acid (9.42%) and the lowest medium-high-molecular weight value (117.49 kDa), and its antioxidant activity was the best. Based on the correlation analysis, the higher uronic acid content, smaller molecular weight, and lower content of monosaccharide composition of glucose for the CPS-UAE might contribute to its higher antioxidant activity. From an industrial viewpoint, ASE technique could be a promising and alternative way to extract CPS due to its high yield, notable antioxidant activity, and convenient industrialization.