Table 1.

Protein extraction technologies applied to seaweeds to disrupt the cell wall.

Extraction Method	Principle	Advantage	Disadvantage	References
Enzyme hydrolysis	Proteolytic/carbohydrase enzymes are applied to degrade polysaccharide components within algal cell walls, releasing target proteins.	Limited use of organic solvents; specific and mild technique for extracting protein and bioactive components	Long extraction times; enzyme preparation can be expensive and require specific temperature and pH.	[29,39,40,41]
Microwave-assisted extraction	The extraction of target compounds occurs through the application of electromagnetic radiation, resulting in the breakdown of the bonds within the algal cell wall. Rapidly heating the sample solvent mixture results in wide-ranging applicability for the rapid extraction of analytes, including thermally unstable substances.	Environmentally friendly technique as it requires no organic solvents and short extraction times	Use in dried seaweed biomass may be limited.	[39,42,43]
Ultrasound-assisted extraction	The use of an acoustic cavitation technique to produce vapor bubbles in the extraction mixture that contributes to the disruption of polysaccharide components in seaweed biomass, thereby releasing proteins.	Fast processing time, low energy consumption, thermal sensitive technique, and limited use of organic solvents	Potential structural changes within polysaccharide structure.	[10,42,44]
Pulse electric field	The generation of high voltage facilitates protein extraction by electroporation, which disrupts the cell membrane of seaweed.	Non-thermal, energy efficient technique	Limitations on scaling up.	[44,45,46,47]
Solid–liquid extraction	Utilises different acid and alkaline conditions with water to facilitate the breakdown of hydrogen bonding in algal cell walls.	Simple and cost effective	Partial degradation of the proteins and bioactive components and time consuming.	[48,49,50]