Patent ID: 7531346

Claim:
A decolorized yeast cell wall fraction prepared by decolorizing cell residue obtained by removing internal soluble cell components from enzyme-treated yeast, or cell residue obtained by further treating the cell residue with acid solution and removing acid solution-soluble components, by using a decolorizing agent, and washing with water or organic solvent; whose yellow index (YI) of the liquid measured by a reflective method with the use of SE-2000 of Nippon Denshoku, with illumination C, field of view 2 degree, is 13 or less; and whose oxygen permeability is 250 ml/m 2 d MPa or less at a humidity of 60% RH when 5% (weight ratio) slurry of the decolorized yeast cell wall fraction is cast using a baker applicator, on an oriented-polypropylene film Senesi-POP of Daicel Chemical Industries, at a film membrane thickness of 0.02 mm, dried for 45 minutes in an oven at 60° C. to make a casting film whose film membrane thickness is approximately 0.015 mm; said decolorized yeast cell wall fraction having a cell wall retaining property, and having a property to form continuous film; wherein a disintegration time of the continuous film formed from the decolorized yeast cell wall fraction in pure water is within 60 minutes when 5% (weight ratio) slurry of the decolorized yeast cell wall is dried for 2 hours at 60° C. in a circular container with a diameter of 60 mm to make a casting film with a film membrane thickness of approximately 0.1 mm.