Laminarin and Laminarin Oligosaccharides Originating from Brown Algae: Preparation, Biological Activities, and Potential Applications

Brown algae is one of the three major types of marine algae and includes approximately 2000 species. It is widely distributed in various seas around the world. Brown algae contain a plethora of active substances, such as polysaccharides, polyphenols, omega-3 fatty acids, and carotenoids. Laminarin, a type of storage carbohydrate found abundantly in brown algae, is mainly formed by glucose monomers linked by β-1,3-glucosidic bonds and partial β-1,6-glucosidic bonds. Laminarin and laminarin oligosaccharides, which contain 2–10 saccharide units, have extensive biological activities, such as antitumor, antioxidant, anti-inflammatory, and prebiotic properties. Moreover, both laminarin and laminarin oligosaccharides can be considered as ideal substrates for bioethanol production because they are composed of abundant glucose residues. Therefore, brown algae-derived laminarin and laminarin oligosaccharides have various potential applications in the food, medicine, cosmetics, and bioenergy fields. This paper reviews the preparation methods of laminarin and laminarin oligosaccharides, as well as their biological activities and potential applications.