Abstract:In this study，the extraction conditions of water-soluble polysaccharide from bagasse as a raw material were optimized by single factor and orthogonal experiments.Then，the extraction conditions were analyzed by ultraviolet（UV）absorption scanning and infrared spectroscopy.First，pectinase，cellulase，and neutral protease were used to compare the individual extraction rate.Cellulase had the highest extraction rate.The optimized process conditions for the enzyme-assisted cellulase combined with the ultrasonic optimization experiment using poor and variance analyses were as follows：material-liquid concentration 1∶30（g/mL）；enzyme solution pH5.0；cellulase concentration 4.5%of the substrate mass；ultrasonic digestion time 60 min；ultrasonic enzyme solution temperature 55 ℃；and ultrasonic power 350 W.The average extraction yield was 12.78%，which was 16.78%higher than that before optimization.The UV absorption spectrum did not show the characteristic absorption peak at wavelengths between 260 nm and 280 nm，suggesting that the crude polysaccharide did not contain nucleic acids or proteins.The stretching vibration spectrum of the functional group detected by infrared spectrum revealed that the extracted substance conformed to the basic characteristics of the polysaccharide，further demonstrating the extraction process′s reliability.