Food Science and Technology Department
"OCHRATOXIN A”: Evaluation of Methodologies for Determination of Ochratoxin A in Food Commodities, Contamination Levels in Different Products Available in the US Market and Evaluation of Fungal Microbiota Associated with Some of the Products
Date of this Version
Ochratoxin A (OTA) is one of the important mycotoxins that contaminate a wide range of food commodities available in the market. In this study, methodologies for analyzing OTA in commodities such as, roasted coffee, cocoa and meat were evaluated. The methods with the best recovery rates were used to analyze the incidence of OTA in these food products. Among different samples analyzed, predominantly 35% of the cocoa samples and 3% of meat samples were contaminated with OTA. Decaffeinated coffee samples showed the highest incidence of contamination (16.7%). Also as a part of this study, Veratox TM (Neogen, MI) ELISA test kit was validated for quantification of OTA in meat using a modified extraction method. Results for recovery, repeatability, cross-reactivity and robustness and linearity showed that the method was suitable for the analysis. Incidence of OTA levels in dried fruits was evaluated and among them raisins and dates showed high levels of incidence of OTA (100% and 70%, respectively). Fungal microbiota was also isolated from dried fruits was characterized and different strains of A. niger and A. tubingensis were identified. All the characterized isolates were tested for OTA production and 36.8% among them were OTA producers. Most of the OTA producers were identified as Aspergillus niger or Aspergillus tubingensis.
Adviser: Andreia Bianchini
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Food Science and Technology, Under the Supervision of Professor Andreia Bianchini. Lincoln, Nebraska: May 2013
Copyright (c) 2013 Lakshmi Gompa