Development of a Competitive Enzyme Immunoassay Technique for the Detection of Soy Traces in Meat Products

The aim of this work was to develop a competitive enzyme immunoassay technique, to detect the presence of traces of soy in meat products. Specific rabbit polyclonal antiserum against soy protein was used as primary antibody. The optimal antigen concentration to be immobilized on the plate and the concentration of primary antibody to be used in competition was determined. The calibration curve was fitted using increasing concentrations of an extract of soy product. The soy product was extracted with Tris-HCl buffer 0.0625M with 3% sodium dodecylsulfate and 2% mercaptoethanol. The working range used in the enzyme immunoassay to detect soy was 9-280ppm SP with adequate linearity (R2: 0.9880). All validation parameters studied were appropriate. Commercial samples of meat products were analyzed with this enzyme immunoassays and a commercial ELISA kit. Significant differences were observed in the quantitative results obtained with both methods; nevertheless the developed enzyme immunoassay could be used as screening method.