The invention discloses a preparation method and an application of an
ethanol extract of
laminarin. The
ethanol extract of
laminarin is obtained through the preparation method which comprises the following steps: 1, crushing sea tangle, adding an
ethanol solution to the crushed sea tangle, extracting for 2-5h at 50-80DEG C; 2, filtering to remove a residue, and adding
active carbon to an extract to decolor and remove a fishy smell; and 3, filtering, and concentrating to obtain the ethanol extract of
laminarin. The ethanol extract of laminarin is added to
cut tobaccos or filter tips in a sprinkling mode, and the
mass of the ethanol extract of laminarin accounts for 0.01-1.0% of the
mass of
cut tobaccos, so the content of free radicals in a mainstream
smoke of cigarettes is effectively reduced, the reduction amplitude of the content of the free radicals is more than 15%, and the smoking quality of the cigarettes is improved, thereby the ethanol extract of laminarin, which has irritationreduction effects on nasal cavities, throats and the like, allows the
smoke to be smooth, the taste to be soft, the fragrance to be kept, and no side effects to be possessed. The ethanol extract of laminarin has the advantages of no obviously fishy smell, easy obtaining, and low cost.