Enzymatic cell wall degradation combined with pulsed electric fields increases yields of water-soluble-protein extraction from the green marine macroalga Ulva sp.

Marine macroalgae are an attractive source of alternative protein. However, protein extraction from macroalgae is challenging. In this work, we investigated a combination of enzymatic cell wall degradation and high voltage Pulsed Electric Fields (PEF), to enhance yields of water-soluble-protein extraction from the green marine macroalga Ulva sp. The combined process showed a considerably higher protein extraction yield (19.6 ± 0.33%) compared to that of PEF alone (10.8 ± 0.37%) and enzyme pretreatment alone (9.7 ± 0.42%). Moreover, the water-soluble-protein extract obtained by PEF, which followed enzymatic cell wall degradation, had significant antioxidant activity. These results indicate that PEF combined with enzymatic pretreatment could contribute to protein extraction yields from Ulva sp., as a part of sustainable seaweed biorefinery. Although several previous works reported on methods for protein extraction from seaweeds for food application, the commercialization of the seaweed proteins is challenging due to multiple challenges in the extraction process development. In this work we show that a combination of enzymes for cell wall degradation with high voltage pulsed electric fields for membrane permeabilization lead to higher yields of water-soluble proteins. Both enzyme treatment and PEF are scalable processes, which do not modify proteins chemically, potentially leading to higher quality of the extract in comparison to standard alkaline extraction with a need to treat chemical waste.