Kelp is one of the major economic algae in China, with abundant resources and annual production ranking among the top in the world.As a medicinal and edible food, kelp is rich in dietary fiber, protein, vitamins, minerals and other nutrients, which is popular with many consumers.The iodine, polysaccharides, active peptides, mannitol and other functional active substances in kelp have physiological function, such as anti-Alzheimer disease, antithrombotic, anti-cancer, anti-inflammation and blood pressure lowering, which can be developed into biomedical products with significant therapeutic effects.In addition, kelp has applications in beauty products, medical textiles, feed and fertilizer, which has a broad development prospect.In this paper, the comprehensive application of kelp in food, biomedical products, feed, fertilizer and other fields as well as the study of active substances were reviewed, with a view to providing reference ideas for developing new kelp products and promoting the high-quality development of kelp industry.

The output of Laminaria japonica is huge in China,but there are less L.japonica deep-processing products.L.japonica green protection is one of the important factors restricting deep-processing.The chlorosis of L.japonica is caused by H⁺ replacing Mg²⁺ in the porphyrin ring of chlorophyll,resulting in the formation of pheophytin,which makes L.japonica lose green.In view of the discoloration and chlorosis of L.japonica during processing and storage,this paper summarized the discoloration mechanism of L.japonica and the common green protection technologies in processing,in order to provide enlightenment for the green protection technologies direction of L.japonica.