Aflatoxins and Ochratoxin A Content of Stored Yemeni Coffee Beans and Effect of Roasting on Mycotoxin Contamination
Keywords:Ochratoxin A (OTA), aflatoxins, ELISA kit, green and roasted coffee beans, Yemen.
This study was aimed to determine the natural occurrence of ochratoxin A (OTA) and total aflatoxins (B1, B2, G1, and G2) (AFs) of stored Yemeni green and roasted coffee beans. A total of 50 samples (25 samples each) were collected randomly from different markets in Sana'a city, Yemen during 2013, and quantitative assessment of these two types of mycotoxins was done using ELISA test kits. In addition, the influence of roasting on OTA and AFs contamination of green coffee beans was also investigated using the pan roasting method. Our results showed that all green and roasted coffee bean samples examined were contaminated with OTA, at concentrations ranging from 1.114 to 18.667 ppb and 1.646 to 31.077 ppb respectively. Also, all green and roasted coffee bean samples examined were contaminated with AFs, at concentrations ranging from 14.694 to 27.176 ppb and 14.255 to 23.231 ppb respectively. In addition, the roasting of contaminated green coffee bean samples with different concentrations of OTA and AFs reduced OTA and AFs levels to 86% and 20% from the initial concentration, respectively. These results indicate that there are risks of mycotoxin contamination of stored Yemeni green and roasted coffee beans.