Dongwon F&B said Thursday it has adopted a nitrogen-flush packaging method for its Yangban brand roasted seaweed, part of a push to expand exports as the company marks the 40th anniversary of the product's launch. The technique reduces oxygen inside the package and replaces it with nitrogen, which is far less reactive. Oxygen triggers oxidation in the oil used to season the seaweed, causing it to develop an off-flavor and lose its crispness over time, while nitrogen helps preserve the fresh, crunchy texture of seaweed straight off the roaster. The company said the method also allows it to maintain the same quality without silica gel packets, the small moisture-absorbing sachets commonly found in packaged foods, cutting about 300 tons of silica gel use per year. The shift is aimed largely at overseas markets, where longer shipping times can leave seaweed soggy by the time it reaches customers. For export products, Dongwon F&B is combining the nitrogen-flush method with silica gel packets, extending the shelf life from six months to 12 months. Yangban seaweed is currently sold in more than