A comparison between enzyme immunoassay and HPLC for ochratoxin A detection in green, roasted and instant coffee

• Autor(a) principal: Fujii,Simone
• Data de Publicação: 2007
• Outros Autores: Ono,Elisabete Yurie Sataque, Ribeiro,Ricardo Marcelo Reche, Assunção,Fernanda Garcia Algarte, Takabayashi,Cássia Reika, Oliveira,Tereza Cristina Rocha Moreira de, Itano,Eiko Nakagawa, Ueno,Yoshio, Kawamura,Osamu, Hirooka,Elisa Yoko
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Archives of Biology and Technology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000200020
• topic: Ochratoxin; immunoassay; HPLC; monoclonal antibody; coffee

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for ochratoxin A (OTA) detection in green, roasted and instant coffees was developed using anti-OTA monoclonal antibody. Immunological reagents prepared were OTA-BSA (4.76 mg/mL), anti-OTA.7 MAb (2x10³-fold dilution) and HRP-anti IgG (10³-fold dilution). The detection limit was 3.73 ng OTA/g and correlation coefficients (r) between this immunoassay and high performance liquid chromatography were 0.98 for green coffee, 0.98 for roasted and 0.86 for instant. OTA levels detected by ic-ELISA were higher than by HPLC, with ELISA/HPLC ratio of 0.66 - 1.46 (green coffee), 0.96 - 1.11 (roasted) and 0.93 - 1.82 (instant). ELISA recoveries for OTA added to coffee (5 - 70 ng/g) were 81.53 % for green coffee, 46.73 % for roasted and 64.35 % for instant, while recoveries by HPLC were 80.54 %, 45.91 % and 55.15 %, respectively. Matrices interferences were minimized by samples dilution before carrying out the ELISA assay. The results indicate that MAb-based ic-ELISA could be a simple, sensitive and specific screening tool for OTA detection, contributing to quality and safety of coffee products.