Both water soluble and insoluble forms of laminarin exist depending mainly on the level of branching. Highly branched laminarin is soluble in both cold water and hot water. However, laminarin with low level of branching is soluble only in hot water (Miao et al., 1995). Unlike other algal polysaccharides (e.g. agar, alginate and carrageenan), laminarin does not have thickening and gelling properties (Rupérez et al.,2002).
Different approaches have been employed to extract laminarin. In general, these processes involve grinding, precipitation in an acid or basic medium, ultrafiltration and dialysis (Yvin et al., 1999). Various approaches reported for extraction of laminarin are summarised in Table 2. Laminarin can be extracted efficiently using high temperature conditions ranging from 50 to 90 °C with water as a solvent. Zhaet al. (2012) studied the effect of the ratio of dried seaweed Laminaria japonica to water on the efficiency of laminarin extraction.