Blue pigment and method for producing same
The purpose of the present invention is to provide: a Gardenia blue pigment which contains a product of a reaction between genipin and a compound having a primary amino group, and which offers a bright, fresh blue color tone having reduced redness; and a method for producing same. This Gardenia blue pigment, which offers a bright, fresh blue color tone having reduced redness, is obtained by carrying out a first step in which genipin and at least one peptide selected from the group consisting of soybean peptides, sesame peptides, and rice peptides are reacted in a solvent without supplying an oxygen-containing gas, and a second step in which a reaction liquid obtained in the first step is processed under an oxygen-containing gas supply.
1 . A blue pigment comprising a reaction product of a primary amino group-containing compound and genipin,
wherein when the blue pigment is diluted with water to obtain a solution having a color value E 10% 1 cm of 0.1, an L* value is 66 or more, an a* value is −24 or less, and a b* value is −25 or more in an Lab color space.
2 . The blue pigment according to claim 1 , wherein when operations (1) to (3) below are performed, a color difference ΔE* ab between a solution A heat-treated at 90° C. for 15 minutes and a solution B not heat-treated is 3.5 or less, and the solution A heat-treated at 90° C. for 15 minutes has an L* value of 64 or more, an a* value of −14 or less, and a b* value of −31 or more;
operation conditions are:
(1) a preparation, wherein
the blue pigment is diluted with a 0.1 M citrate buffer solution having a pH of 2.5 to prepare a solution A having a color value E 10% 1 cm of 0.1, and the blue pigment is diluted with a 0.1 M citrate buffer solution having a pH of 6.0 to prepare a solution B having a color value E 10% 1 cm of 0.1;
(2) a heat treatment of the solutions, wherein
the solution A is heat-treated at 90° C. for 15 minutes, and the solution B is not heat-treated; and
(3) measurement of color tone, wherein
the L* value, the a* value, and the b* value in the Lab color space are measured for the solution A heat-treated at 90° C. for 15 minutes and the solution B not heat-treated.
3 . The blue pigment according to claim 1 , wherein a maximum absorption wavelength is present in a region of 604 nm or more.
4 . The blue pigment according to claim 1 , wherein the genipin is derived from Gardenia of the family Rubiaceae, Genipa americana , or a genetically modified microorganism.
5 . A food or beverage product colored with the blue pigment according to claim 1 .