Abstract:With sweet potato residues as raw materials，soluble dietary fiber（SDF） was extracted from sweet potato residues by ultrasound-assisted enzymatic modification. Single-factor experiments were conducted by selecting five influencing factors：cellulase addition amount，xylanase addition amount，ultrasound temperature，ultrasound power，and ultrasound time. Based on this，the Box Behnken method was used to optimize the extraction process of SDF from sweet potato residues. At the same time，the SDF from sweet potato residues treated with ultrasound-assisted enzymatic modification was applied to sweet potato beverages，and its effects on the sensory，color，rheological characteristics，stability，and biological activity of the beverage were studied. The results showed that the optimal process parameters for extracting SDF from sweet potato residues by ultrasoundassisted enzymatic modification were as follows：ultrasound time of 32 min，ultrasound temperature of 50 ℃，ultrasound power of 384 W，cellulase addition amount of 1.21%，and xylanase addition amount of 1.17%，achieving an extraction yield of 12.04%. When the addition amount of SDF from sweet potato residues was in the range of 0%-9%，as the addition amount of SDF increased，the viscosity and stability of the beverage increased，and the ability to scavenge DPPH free radicals and adsorb nitrite was enhanced，which hindered glucose diffusion more significantly. Compared with that of sweet potato beverages without SDF from sweet potato residues，the sensory score of sweet potato beverages significantly decreased when the addition amount of SDF from sweet potato residues exceeded 5%. Therefore，the addition amount should be controlled within 5%.