Low-cost grain sorting technologies to reduce mycotoxin contamination in maize and groundnut

Area of Science:

• Agricultural Science
• Food Safety
• Mycotoxicology

Background:

• Mycotoxin contamination in staple foods like maize and groundnuts poses a significant public health risk in sub-Saharan Africa.
• Aflatoxins (AF) and fumonisins (FUM) are prevalent mycotoxins requiring effective mitigation strategies.
• Current methods for mycotoxin reduction are often costly or inaccessible.

Purpose of the Study:

• To evaluate the efficacy of grain sorting techniques in reducing mycotoxin contamination in maize and groundnut.
• To identify key kernel physical properties associated with mycotoxin levels.
• To assess low-cost sorting technologies for practical application.

Main Methods:

• Tested various sorting principles including kernel bulk density (KBD), 100-kernel weight (HKW), size, and visual sorting.
• Developed and evaluated a low-cost prototype sorter (DropSort) based on KBD and HKW.
• Analyzed individual kernel physical characteristics (weight, volume, density, dimensions, sphericity) in relation to mycotoxin content.
• Assessed combined sorting strategies (e.g., size followed by DropSorting).

Main Results:

• Kernel bulk density and 100-kernel weight were correlated with aflatoxin and fumonisin levels in maize.
• The DropSort device effectively reduced fumonisins but was less effective for aflatoxins in maize.
• Single kernel weight was the strongest predictor of aflatoxin concentration in maize.
• Size and visual sorting were more effective than DropSort for reducing aflatoxins in groundnuts.

Conclusions:

• Grain sorting, particularly based on physical properties like kernel weight and density, can reduce mycotoxin contamination in maize.
• Different sorting methods show varying effectiveness for different mycotoxins and commodities (maize vs. groundnut).
• Low-cost sorting technologies and combined approaches show promise for improving food safety in resource-limited settings.