title: Enzyme immunoassay for phycocyanin as the main component of spirulina color in foods.
abstract: An enzyme immunoassay (EIA) for phycocyanin in foods was developed. Anti-phycocyanin monoclonal antibodies were obtained from A/J mice immunized with phycocyanin. The phycocyanin in a food was extracted by dissolving the sample in a borate buffer solution, pH 8.0 (BBS) and adjusting the pH value of this solution to 8.0 with NaOH. The extract was then diluted more than 10 fold with 1% gelatin in BBS. Phycocyanin was determined by avidin-biotin sandwich EIA, using the P26-8 monoclonal antibody as the solid-phase antibody and the P277-4 monoclonal antibody as the enzyme-labeled antibody. The working range for a quantitative analysis was 100-1000 ng/ml, and the detection limit was 10 micrograms/g of the original sample. Recoveries of phycocyanin from foods by this assay were > 71% for candy, and > 66% for ice cream and sherbet. Phycocyanin was assayed in 22 blue-, green-, purple-, and brown-colored commercial foods, and detected in one green colored-jelly at 49 micrograms/g.
authors.affiliation: Osaka Prefectural Institute of Public Health, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Yoshida
authors.forename: Y
authors.initials: Y
authors.lastname: Takagaki
authors.forename: T
authors.initials: T
authors.lastname: Nishimune
mesh_terms: D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D001710:Biotin / Q000737:chemistry; D002021:Buffers; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005504:Food Analysis; D005505:Food Coloring Agents / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007124:Immunoenzyme Techniques; D010798:Phycocyanin / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D002021:Buffers; D005505:Food Coloring Agents; D010798:Phycocyanin; D001710:Biotin