The invention relates to a method for preparing
gardenia blue
pigment by utilizing immobilized
yeast cells. The method comprises the following steps of: a) inoculating a
yeast strain for producing beta-glucuroide to a culture medium, fermenting to obtain a bacterial liquid, centrifuging the bacterial liquid, embedding a substratum bacterial liquid by using a
sodium alginate solution to form a
sodium alginate-saccharomycete suspension, and dripping the
sodium alginate-saccharomycete suspension into a
calcium chloride solution dropwise to form the immobilized
yeast cells; b) stirring and mixing a geniposide solution, an
amino acid solution and the immobilized yeast cells to obtain a
gardenia blue solution; and c) adding the
gardenia blue solution into a column which consists of macroporous alkalescent
styrene anion exchange resin, eluting by using an
ethanol solution, collecting eluent, concentrating the eluent, and spray-
drying a concentrated solution to obtain gardenia blue
powder. According to the method, a saccharomycete
fermentation liquid is immobilized directly without treatment, so that the problems of difficulty in separation of yeast and products, high possibility of loss and the like by the conventional method for performing
fermentation by free yeast are solved, and the purity of the gardenia blue is improved.