Determination of Ochratoxin A and Its Metabolite Ochratoxin Alpha in Different Food Matrices After Enzymatic Biotransformation

Ochraxotina A (OTA) is a mycotoxin which has carcinogenic, nephrotoxic, and teratogenic effects, and it is found at different levels and matrices. As consequence, the development of methods capable of reducing this contamination to levels permitted by legislation is encouraged, with emphasis on the enzymatic process that enables the hydrolysis of OTA to a nontoxic metabolite (OT alpha) under mild reaction conditions. Therefore, the objectives of this work were to optimize the DLLME (dispersive liquid-liquid microextraction) for OTA and OT alpha determination and to study the kinetic of OTA enzymatic hydrolyses intending its application in the food chain. First, the optimization of the DLLME extraction technique for OTA and OT alpha was performed, obtaining as an ideal condition the use of 100 mu L of 1-octanol (extractor solvent) and 2000 mu L of ethyl acetate (dispersant solvent). After the validation, the proposed method was successfully applied during the optimization of OTA biotransformation into OT alpha. The ideal conditions for OTA hydrolysis were the use of pancreatin (ratio 1 ng OTA:2.7 mg protein) at 50 degrees C. At these conditions, a kinetic study was conducted and a prediction model for OTA degradation was established based on logarithmic curves. In this study, an innovative method for OTA and OT alpha detection was developed and with this method, it was possible to study the kinetic of OTA hydrolysis in a fast, reliable, safe, and environmentally friendly manner. Through this kinetic study, the enzymatic hydrolyses developed can be used as a guidance to assure the biotransformation of OTA in different food matrices.

Automated summary

In this study, a method for the detection of OTA and OT alpha was developed using DLLME technique, and the enzymatic hydrolysis of OTA was studied. A prediction model for OTA degradation was established based on the kinetic study, providing guidance for OTA biotransformation in different food matrices.