PROBLEM TO BE SOLVED: To provide a particle which is excellent in dispersion stability under acidic conditions and suppresses coloration under acidic and high-temperature conditions.SOLUTION: A particle is obtained by preparing a hydrophobic liquid from an antibioactive compound and a hydrophobic polymerizable vinyl monomer, emulsifying the hydrophobic liquid in water in the presence of a cationic compound and mini-emulsion-polymerizing the polymerizable vinyl monomer.