Extraction, structure and biofunctional activities of laminarin from brown algae

Summary 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 β‐glucan, is composed of (1,3)‐β‐ d ‐glucan and some β‐(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.