Extraction, structure and biofunctional activities of laminarin from brown algae

Brown algae are rich sources of bioactive compounds such as polysaccharides, peptides, omega-3 fatty acids, carotenoids, phenolics, vitamins and minerals. Laminarin is low-molecular-weight polysaccharide and bioactive compound present in brown algae. Laminarin is found in the fronds of Laminaria and Saccharina species. Laminarin, a storage beta-glucan, is composed of (1,3)-beta-D-glucan and some beta-(1,6)-intrachain links. The reported content of laminarin from brown algae is up to levels of 35% on dry basis, which varies depending on species, harvesting season, habitat and method of extraction. Laminarin has many reported biofunctional activities including antitumour, anti-apoptotic, anti-inflammatory, anticoagulant and antioxidant activity. Biofunctional activities of laminarin can be enhanced after suitable chemical modifications, sulphation and novel processing techniques. Studies on feeding of laminarin-rich extracts to animals indicate it's suitability as functional ingredient for food applications. This paper reviews the main sources, structure and extraction of laminarin with its biofunctional activities.