Synergy of cold-induced aggregation and centrifugation to enhance microfiltration performance and protein purity in water-based pea protein extraction

Avoiding the use of chemicals during the extraction of commercial pea proteins is crucial to preserve protein nativity and ensure sustainability, which is best achieved through water-only extraction coupled with membrane filtration. To minimize membrane fouling during filtration, this study evaluated various storage and centrifugation pretreatments of the pea extract to remove suspended solids prior to pilot-scale microfiltration (MF). Inducing aggregation via storage followed by centrifugations improved the flux significantly, where the cold-induced aggregation and centrifugation of the extract achieved nearly four times higher steady flux than the control. This flux improvement was due to the selective removal of aggregated legumin proteins during cooling and centrifugation, resulting in coextraction of pellets with protein purity >90%. Ultrafiltration (UF) of the same treated sample showed slightly improved flux compared to the control, suggesting that fine-tuning the feed pretreatments with the membrane pore size is of importance. It was confirmed that the proteins had no major secondary structure changes across all pretreatments. Measured viscoelastic properties indicated that all the supernatants have formed stronger gel networks than pellets. Overall, coupling storage and centrifugation conditions as a pretreatment of pea extract before MF enhances filtration performance and enables the extraction of highly pure native proteins using only water, laying groundwork for a scalable approach for sustainable pea protein production. • Cold storage and centrifugation of pea extract enable selective removal of legumin. • Removal of legumin from pea extract enhances flux during filtration. • Cold-induced aggregation at 4°C doesn't cause pea protein denaturation. • UF is less responsive to the pretreatment of pea extract compared to MF. • The effectiveness of pea extract pretreatment depends on the membrane pore size.