Examining the Research Gap in Aflatoxin Risk Management in Groundnut Post-Harvest Systems in Northern Nigeria

Aflatoxin contamination of groundnut in post-harvest storage and processing is a major food safety and export market access barrier in Nigeria's major groundnut producing states, but the specific post-harvest system interventions most effective for aflatoxin risk reduction in northern Nigerian conditions have been insufficiently evaluated. This study examined the research gap in aflatoxin risk management in northern Nigerian groundnut post-harvest systems through systematic literature review and an original field assessment. A scoping review of 12 databases identified 54 publications from 2018 to 2024 addressing aflatoxin in Nigerian groundnut, of which only 11 evaluated specific post-harvest management interventions under Nigerian field conditions. Pre-harvest interventions (biocontrol using Aflasafe NG01) were well studied, but drying method, storage material, and processing-stage risk factor characterisation were under-represented. Original field assessment across 60 groundnut farms and traders in Kano, Jigawa, and Katsina States documented aflatoxin levels at five post-harvest chain points (farm gate at harvest, after field drying, after storage at 3 months, at market trader, and at processor). Aflatoxin levels above the EU limit of 4 ppb were found in 33 percent of farm-gate samples, rising to 69 percent at 3-month storage. Field drying duration and storage bag type were significantly associated with aflatoxin increase. The study identifies four critical research gaps and proposes a controlled experiment design for evaluating combined aflatoxin risk reduction interventions.

Keywords: aflatoxin, groundnut, post-harvest management, northern Nigeria, food safety