ENZYMATIC AND IMMUNOLOGICAL APPROACHES FOR THE QUANTITATION AND CONFIRMATION OF OCHRATOXIN-A IN SWINE KIDNEYS

Several techniques for the quantitation and confirmation of ochratoxin A (OA) in swine kidneys were examined. Naturally and artificially con taminated swine kidneys were analyzed for OA by conventional high-perf ormance liquid chromatography (HPLC) analysis. Samples were additional ly tested by enzyme-linked immunosorbent assay (ELISA) or treated with carboxypeptidase A followed by HPLC analysis (enzymatic method). Corr elations (I values) between the conventional HPLC procedure and the EL ISA, using artificially contaminated samples, were 0.88 and 0.81 (P <0 .05) respectively, while the corresponding values between the conventi onal HPLC procedure and the enzymatic method were 0.89 and 0.98 (P <0. 05). The ELISA gave a more direct estimation of OA contamination than the enzymatic procedure. The enzymatic method also had a reproducible tendency to underestimate or overestimate the amounts of OA in kidney. This was found to be dependent on the source of contamination, as art ificially and naturally contaminated kidney samples resulted in linear regression analysis slopes of 0.38 and 2.8, whereas the slopes for th e ELISA method were 1.13 and 0.92, respectively. The results with the naturally contaminated kidneys suggest that other naturally occurring forms of OA also occurred in swine kidney. Regardless of this effect, the enzymatic method accurately confirms the presence of OA and relate d compounds in kidney. The techniques are simple and will complement c onventional HPLC analysis for the detection, quantitation, and confirm ation of OA in swine kidneys.