Biorefinery of the macroalgae Ulva lactuca: extraction of proteins and carbohydrates by mild disintegration

The effect of osmotic shock, enzymatic incubation, pulsed electric field, and high shear homogenization on the release of water-soluble proteins and carbohydrates from the green alga Ulva lactuca was investigated in this screening study. For osmotic shock, both temperature and incubation time had a significant influence on the release with an optimum at 30 degrees C for 24 h of incubation. For enzymatic incubation, pectinase demonstrated being the most promising enzyme for both protein and carbohydrate release. Pulsed electric field treatment was most optimal at an electric field strength of 7.5 kV cm(-1) with 0.05 ms pulses and a specific energy input relative to the released protein as low as 6.6 kWh kg(prot)(-1). Regarding literature, this study reported the highest protein (similar to 39%) and carbohydrate (similar to 51%) yields of the four technologies using high shear homogenization. Additionally, an energy reduction up to 86% was achieved by applying a novel two-phase (macrostructure size reduction and cell disintegration) technique.