Analysis of Selected Mycotoxins in Maize from North-West South Africa Using High Performance Liquid Chromatography (HPLC) and Other Analytical Techniques

Abstract

Contamination of foods by mycotoxins is linked to various health and economic implications. This study evaluated the incidence of mycotoxins in commercial and small-scale maize and evaluated potential health risks for consumers based on South African and international regulations. The sensitivity/specificity of HPLC over other analytical methods used was also ascertained. In total, 100 maize samples were analyzed using immuno-affinity column for extraction and clean-up, thin layer chromatography (TLC), HPLC, and enzyme linked immunosorbent assay (ELISA) for quantification. Results revealed that fumonisinB1 was the most contaminant mycotoxin in both small-scale and commercial samples with incidence rates of 100% and 98.6%, respectively. Aflatoxins contamination occurred at incidences of 26.7% in small-scale and 25.0% in commercial samples. Furthermore, ochratoxin A had high incidence rates of 97.8% and 93.0% and ranged from 3.60–19.44 µg/kg and 1.60–9.89 µg/kg, respectively, in small-scale and commercial samples, while ZEA occurred in 50% and 55% of small-scale and commercial samples, respectively. Results demonstrate that maize, especially from small-scale farmers, may contribute to dietary exposure to mycotoxins. Farmers and consumers should be alerted to the dangers of mycotoxins contamination in maize with resultant health risks. Additionally, HPLC method was also found to be more specific for mycotoxin detection than ELISA.

Fumonisins in African Countries

“…The fumonisin levels were significantly higher in maize (101-53,863 µg kg −1 ) as compared with the fumonisin levels in porridge (0.2-20 µg kg −1 ) and faecal samples (0.3-464 µg kg −1 ). Further research indicated that a high proportion of the fumonisins is destroyed in the process of making porridge from the maize [90]. Altogether, 114 samples from maize grown by rural subsistence farmers in two districts of northern South Africa were analysed for fumonisins during two seasons.…”

Fusarium Mycotoxins, Their Metabolites (Free, Emerging, and Masked), Food Safety Concerns, and Health Impacts

“…Implementation of good agricultural practices (GAP), good manufacturing practices (GMP), and hazard analysis and critical control points (HACCP), amongst other measures, have been proposed. The adoption of GAP in the field and during storage, GMP during food processing, and HACCP during food handling and packaging throughout the whole field-to-table chain will go a long way to address the problems caused by fungi and mycotoxins in the food system [121,122].…”

“…(c) Food handling and packaging includes the use of technologies such as modified atmosphere packaging (MAP), which is a useful technology that involves the use of oxygen (O 2 ) absorbents, storage temperature, and packaging film barrier. MAP can be used to prevent fungal growth and mycotoxin contamination on finished products [122,124] Creating awareness of the importance of adopting GAP, GMP, and HACCP to control (prevention and decontamination) mycotoxin metabolites in the food system will be useful in reducing the risk of mycotoxin exposure to some extent. Mycotoxin control strategies should also include approaches for the diversion of contaminated agricultural products to lower-risk uses.…”

Underreported Human Exposure to Mycotoxins: The Case of South Africa

“…These results prompted researchers in SA to focus on Fusarium mycotoxins. From review, major mycotoxin reports from both the subsistence and commercial farming systems show no significant different except for AFs, where a high incidence of AFs were discovered in maize and other foodstuff from small-scale compared to commercial farms [ 19 ]. This indicates that millions of South Africans from rural settlements are exposed to the effects of mycotoxins on a regular basis.…”

“…Most studies on maize are conducted as multi-mycotoxins research. Some of these have revealed the absence of contamination with aflatoxins (AFs) in SA commercial maize [ 3 , 22 , 23 ], while others have reported their presence [ 12 , 13 , 16 , 19 , 24 , 25 , 26 , 27 , 28 ]. Subsistence farmers in SA and their immediate communities are exposed to dietary AFs in maize, milk, carry-over in animal products, and other processed foods daily.…”