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Considered to be a major active component of pumpkin,pumpkin polysaccharides play a significant role in regulating blood sugar level and blood lipid level,as well as in anti-cancer effects.However,its extraction and purification still remain a challenge for further application of pumpkin polysaccharides.In this study,raw pumpkin polysaccharides were concentrated by ultrafiltration under the physical fields such as ultrasonic field and electric field.Under only ultrasonic field,the effect of ultrafiltration time,temperature,ultrasonic power and ultrasonic frequency on the membrane flux of pumpkin polysaccharides was investigated.When electric filed was applied,the electric power and pulse frequency mostly influenced the flux.The flux increased with the increasing of electric power,and it reached the maximum at the pulse frequency of 600 Hz.The flux was greatly improved while the combination of ultrasonic field and electric field was applied.In conclusion,extraneous physical fields had been demonstrated to significantly reduce membrane fouling degree and improve membrane flux recovery rate,thus may further offer a solution t