Overview of Extraction Methods for Extracting Seaweed and its Applications

Abstract

Seaweed is a carbohydrate polymer of alginate, agar, and carrageenan which can be extracted and purified as hydrocolloids. Each carbohydrate has different physicochemical properties and hydrocolloids can form gels when dispersed in water. To achieve targeted hydrocolloids according to specific purposes and functions, conventional extraction methods, and several green extraction methods for extracting seaweed have been proposed and discussed. The conventional extraction method is in the form of solvent extraction (SLE), while the green extraction includes: microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), supercritical fluid extraction (SFE), pressurized solvent extraction (PSE), and reactive extrusion which automatically selectively presented as a promising method for extracting hydrocolloids in seaweed. These methods have been applied by taking into account the recovery rate, time, volume, temperature, pH, ratio, and type of solvent, as well as the type of method. This study discusses extraction methods that can extract bioactive compounds from seaweed with high yields and are economical and environmentally friendly