A review of agricultural aflatoxin management strategies and emerging innovations in sub-Saharan Africa

Abstract

Aflatoxins are highly carcinogenic secondary metabolites produced by Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxin contamination of food and animal feeds is, therefore, a major food security, food safety, trade, human and domestic animal health concern. Researchers worldwide have suggested various agriculture-based strategies to manage aflatoxigenic Aspergillus species and reduce contamination to safe levels. This paper reviews various agricultural strategies that could be employed to reduce contamination of aflatoxins in food crops and animal feeds, as well as the challenges faced by these reduction strategies. Among these strategies are innovations like Aflasafe TM and solar grain driers. It is hoped that this critique will stimulate refinement of the existing aflatoxin control approaches and innovations to maximize their efficacy.

Food Safety and Aflatoxin Control

“…Biological methods include using GMO technology such as providing insect resistance using Bacillus thuringiensis (Monda, 2016). The focus on resistance to insects is due to the high correlation existing between insect damage and aflatoxin contamination.…”

“…GMO technological approaches to aflatoxin management mainly have focused on expression of recombinant insecticidal proteins from Bacillus thuringiensis, expression of antifungal peptides and proteins and the use of Host-Induced Gene Silencing technology. The use of Bacillus thuringiensis toxin technology against the European corn borer has enabled a reduction of aflatoxin levels in maize (Monda, 2016).…”

Variation in Occurrence and Aflatoxigenicity of Aspergillus flavus from Two Climatically Varied Regions in Kenya

“…A. flavus is predominantly a saprophytic fungus residing in the soil and colonizes various environments with rich sources of carbon and nitrogen [16,17]. Various aflatoxin contamination control strategies have been proposed [18,19]; key among them being pre-harvest strategies that include the application of atoxigenic A. flavus strains at the pre-silking stage and good agricultural practices comprising early harvesting and proper drying of the harvested grains to moisture levels below 13% [17,20,21]. However, one major factor that could affect the success of such interventions is knowledge of the level of fungal inoculum in the soil as well as the toxigenicity of the existing isolates.…”

The Hotspot for (Global) One Health in Primary Food Production: Aflatoxin M1 in Dairy Products

“…Here is a list of critical factors (34, 35): Soil contamination by Aspergillus spores may be increased by modern cultivation systems excluding crop rotation, frequent irrigations with fixed modern equipment, and leaving a presence of infested and damaged pods in the field.Cultivar selection that disregard vulnerability to Aspergillus spp. as a selection criterion.…”

“…Strengths and weaknesses of biological control (e.g., breeding for introduction of a atoxigenic strain to the crop environment to compete with toxigenic strain) and enhanced plant resistance (e.g., resistance to the fungus, inhibition of AF biosynthesis, resistance to insects) have been reviewed, as well as relevant challenges in economically developing areas (34, 35). …”