Stirring-assisted dead-end ultrafiltration for protein and polyphenol recovery from purple sweet potato juices: Filtration behavior investigation and HPLC-DAD-ESI-MS2 profiling

The potential of stirring assisted dead-end ultrafiltration (UF) to recover polyphenols from purple sweet potato (PSP) juices was evaluated. For this purpose, the effects of rotation speed (200–600 rpm), transmembrane pressure (TMP) (0.2–0.4 MPa), and membrane molecular weight cut-off (30–100 kDa) were investigated with a lab-scale filtration module. The results showed that the highest protein removal (86%) and polyphenol selectivity (12.2) were both obtained under higher rotation speed (600 rpm). Moreover, filtration flux was more important at 600 rpm due to the anti-fouling effect of shear rate generated by the rotation. The results also revealed that under TMP of 0.4 MPa, the cake resist…