ENZYME-IMMUNOASSAY FOR PHYCOCYANIN AS THE MAIN COMPONENT OF SPIRULINACOLOR IN FOODS

An enzyme immunoassay (EIA) for phycocyanin in foods was developed, An ti-phycocyanin monoclonal antibodies were obtained from A/J mice immun ized with phycocyanin. The phycocyanin in a food was extracted by diss olving the sample in a berate buffer solution, pH 8.0 (BBS) and adjust ing the pH value of this solution to 8.0 with NaOH. The extract was th en diluted more than 10 fold with 1% gelatin in BBS. Phycocyanin was d etermined by avidin-biotin sandwich ETA, using the P26-8 monoclonal an tibody as the solid-phase antibody and the P277-4 monoclonal antibody as the enzyme-labeled antibody. The working range for a quantitative a nalysis was 100-1000 ng/ml, and the detection limit was 10 mu g/g of t he 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 mu g/g.