Strategies to quantify Ochratoxin A in coffee samples: study of interferences, pretreatments and computational analysis.
Name: ISABELA FRACALOSSI MANCINI
Publication date: 29/07/2025
Examining board:
Name |
Role |
|---|---|
| GABRIEL FERNANDES SOUZA DOS SANTOS | Coorientador |
| JAIRO PINTO DE OLIVEIRA | Presidente |
| MARCO CESAR CUNEGUNDES GUIMARAES | Examinador Interno |
| PAULO WAGNNER PEREIRA ANTUNES | Examinador Externo |
Summary: Ochratoxin A (OTA) is a mycotoxin produced by fungi of the Aspergillus and Penicillium genera that can be found in various food products and is particularly relevant in the context of coffee production. Due to its high toxicity, each region has its own regulations to ensure safe maximum consumption limits of this substance in coffee beans. The quantification of OTA is commonly performed using methodologies that involve immunoaffinity columns (IACs) as a pre-treatment step, followed by high- performance liquid chromatography with fluorescence detection (HPLC-FL). However, components of the coffee matrix can directly influence the efficiency of OTA recognition by IAC antibodies. Therefore, the present study investigated individually the influence of some coffee markers (caffeine, caffeic acid, chlorogenic acid, cafestol, acrylamide, and melanoidins) on OTA detection, as well as their effects in different types of coffee. The assays were performed by pre-treating the samples using IACs followed by HPLC- FL detection, and also employing rapid tests (Lateral Flow Immunoassay, LFIA). The results showed that nearly all interferents were capable of reducing OTA recovery in the tests. Caffeine and caffeic acid yielded the lowest recoveries in the HPLC-FL tests, with values of 65.17% and 69.39%, respectively. In the LFIA tests, chlorogenic acid and melanoidins resulted in the lowest recoveries, with only 48.45% and 35.74%, respectively. Computational molecular docking studies were carried out, and the in silico results were compared with the tests performed. The findings indicate that the reduction in toxin recovery may be related to possible interactions with OTA, mainly through hydrogen interactions or - bonds.
