An HPLC-FLD method to measure ochratoxin A in teff (Eragrostis tef) and wheat (Triticum spp.) destined for the local Ethiopian market

Abstract

Wheat (Triticum spp.) is among the top cereal grains in terms of production and consumption in Ethiopia. It can be typically infected with ochratoxin A (OTA) producing fungi both in the field and during storage resulting in animal and human health problems. While there is a wealth of information on the presence of OTA in wheat, the incidence of OTA in teff (Eragrostis tef), a cereal grain produced and consumed traditionally in Ethiopia and Eretria, remains insufficient. The purpose of this study was to develop and validate a high performance liquid chromatography (HPLC) method for OTA analysis in teff and wheat flours and to analyse the characteristic distribution of OTA in teff and wheat flours samples destined for local consumption in Ethiopia using a survey-approach. Wheat and teff flour samples were examined for OTA contamination. OTA was detected in 20% of the teff flour samples and in 50% of the wheat flour samples with median contamination levels of 1.04 μg/kg (limit of detection (LOD) = 0.78 μg/kg) and 7.23 μg/kg (LOD = 0.58 μg/kg) respectively. The validated method for OTA detection and quantification in teff and wheat using HPLC meets the European Union performance criteria for OTA (EC 2006/401) and the Eurachem Guideline validation requirements. An insight into the occurrence of OTA in teff is very valuable because the cereal might provide a lower OTA risk alternative for wheat in Ethiopia. In addition, for the world market, an insight into the occurrence of OTA in teff is important in the light of an increasing interest in teff as a gluten free cereal.

Mycotoxins in Ethiopia: A Review on Prevalence, Economic and Health Impacts

“…Ayalew et al [ 64 ] found that 24% and 27.3% of cereals and teff samples were positive for OTA (2.7–2106 µg/kg), respectively. Another study by Geremew et al [ 57 ] reported the presence of OTA in 20% of teff flour collected from Addis Ababa. These results indicate that OTA contamination is a serious health concern for Ethiopia because injera (flat bread made out of teff) is a daily meal for majority of people in Ethiopia.…”

Foreword WMJ special issue ‘Mycotoxins in Africa’

“…While generally there are a lot of data about ochratoxin A in wheat, this information is rather scarce for Ethiopia and hardly exists for Ethiopian teff. Therefore, Geremew et al (2018) developed an analytical method to determine ochratoxin A in wheat and teff. The method was based on alkaline extraction, solid-phase extraction clean-up and HPLC with fluorescence detection.…”