Unusual pattern of aflatoxins and ochratoxin in commercially grown maize varieties of Pakistan

Abstract

The contamination of food with mycotoxins could be a major health risk. Identification and quantification of mycotoxins in maize are essentially required to guarantee food safety. Seven commonly grown maize cultivars were sown at semi-arid conditions in Pakistan. After harvesting plants, total aflatoxin (AFs), aflatoxins B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁), G₂ (AFG₂), and ochratoxin-A (OTA) contents were determined in maize flour using high performance liquid chromatography (HPLC). Results showed an unusual pattern of AFs in maize with a higher concentration of AFG₁ in all maize varieties. The AFB₁ was not found in most of the samples, however, all maize grains contained AFs above the maximum tolerable limit (20 μg/kg). The highest concentration of AFs was recorded in Ayub-1/26 maize (362.8 μg/kg). Ochratoxin-A (OTA) was detected in 71% maize samples ranged from 2.14 to 214 μg/kg. The highest OTA and microbial load were recorded in Ayub-2/27 grains that exceeded the FDA limit (50 μg/kg). These results indicated the higher prevalence of total AFs, AFG₁, and OTA at the harvest stage of maize that could pose significant health hazards to humans and livestock.

Keywords: Aflatoxin; Fungal load; HPLC; Maize; Ochratoxin-A.