Alginic acid is localised in the cell walls and intercellular spaces of the brown alga, Laminaria japonica Aresch., and the salts of this compound occur mainly as calcium alginates. However, the alginates in this alga do not have the viscosity and the ability to create and stabilise structural products. Hence, the structure and properties of the alginates in Laminaria were changed by chemical modification to produce new products such as sodium alginates and other substances capable of forming gels. The rheological properties of the algal gel from Laminaria depended on the properties of the sodium alginate. Heating the algal product up to 90°C did not change its physical and chemical properties; the viscosity did not differ from that of the initial product. The viscosity and molecular weight of the sodium alginate isolated from the algal gel were stable from 20°C up to 95°C. However, about 30% of the viscosity was lost at 100°C. Recipes and various methods of preparing the gel products as fish sauces, jelly-like fish products, fruit jellies, drinks, cosmetic and pharmaceutical products are presented. The algal gel and the gel products did not lose their integrity with heat processing.