Fixation and stability enhancement of beta-carotene by organo-modified mesoporous silica

β-carotene is one of naturally occurring dyes, and has been used as a colorant because of its nontoxicity and biological functions. However, the color stability of the β-carotene is not sufficient. The aim of this study is to enhance the stability of the β-carotene by incorporation into the pore of mesoporous silica. Although the highly lipophilic β-carotene does not generally meet rather hydrophilic inner pore space of mesoporous silica, the modification of the inner pore by alkyl chains enables the incorporation of the β-carotene into the mesopore. The incorporated β-carotene is successfully stabilized against visible light irradiation. Also improved is the durability of the dye in the composite sample against elution to the solvent. The effect of the complexation on the stability enhancement depends on the affinity of the lipophilic β-carotene to the organo-modified inner pore space.