Pilot Scale Recovery of Proteins from a Pea Whey Discharge by Ultrafiltration

An ultrafiltration process was used to recover proteins in the effluent discharge (pea whey) of a wet milling process for pea protein production. The pea whey prior to ultrafiltration was either centrifugally clarified (10,000×g) to reduce solids load, or bag-filtered (25 µM) to remove abrasive particulates. Ultrafiltration followed by diafiltration increased protein content from 39 g/100 g solids in discharge to 84 g/100 g solids in the recovered protein isolate, and recovered protein in the isolate equivalent to 15 to 52 g/100 g protein in pea. The system performed similarly for feeds from both types of pre-treatment. The working flux of ultrafiltration can be maintained with solids content up to 15 g/100 g concentrate, suggesting a high tolerance of the system to the pea whey. SDSPAGE revealed that the proteins from centrifugally clarified discharge are mostly albumin of 17.5 kDa; a membrane with MWCO 30 kDa failed to retain and purify this protein. Preliminary results indicated that protein isolates from the ultrafiltration process have superior functional properties and nutritive value to the conventional commercial product.