Effect of extraction condition on protein recovery and phenolic interference in Pacific dulse (Devaleraea mollis)

Pacific dulse (Devaleraea mollis), a type of red macroalgae, is of particular interest in the context of plant-based protein given its high protein content. One challenge in utilizing seaweed-derived protein is the poor protein recovery/yield and high cost that limits wider adaptation. In this study we aimed to evaluate methods for protein extraction from Pacific dulse to achieve a higher protein recovery rate. We evaluated the effect of cellulase treatment, under two extraction approaches, on the protein recovery and phenolic interference in Pacific dulse extracts. Commercial cellulases Viscozyme and Celluclast (2%, v/v) improved crude protein recoveries in both aqueous-alkaline and sequential protein fractionation approaches. The use of Osborne method to sequentially recover water-, saline-, alkaline-, and ethanol-soluble protein fractions resulted in more than a threefold increase in yield even at low-temperature conditions, mainly with the recovery of more protein in both albumin and globulin fractions. Without cellulase treatment, extending extraction time provides no improvement in protein yield but rather favors an increase in phenolic interference. Collectively, these results show that cellulase-aided sequential protein extraction can be used for improved protein recovery from Pacific dulse.