Method for extracting carrageenan by using enzyme process instead of alkaline process

The invention discloses a method for extracting carrageenan by using an enzyme process instead of an alkaline process. The method comprises the following steps: washing and soaking eucheuma; adding neutral cellulase and neutral protease for first enzyme treatment; adding a metal chelating agent to remove heavy metal ions; filtering out the reaction liquid, adding appropriate water and heating for glue cooking; after rough filtration, adding macroporous adsorption resin for decoloration; after the decoloration, performing refined filtration while the glue is hot; after the glue solution is cooled, adding sulfatase for secondary enzyme treatment; after the enzyme treatment, adding potassium chloride gel; putting the gel into a nylon bag, and wrapping and dehydrating under oil pressure to obtain solid gel; and drying and grinding to obtain a carrageenan product. In the invention, by adopting a bio-enzyme treatment technology to replace traditional alkaline process, the loss of colloid can be effectively reduced, and the energy consumption and environmental pollution are reduced; and by adopting the macroporous adsorption resin for the decoloration treatment, the problems of a sodium hypochlorite process such as frequent damage of molecular structure of carrageenan, unstable product quality, chloride ion residue and environmental pollution are avoided.