Post-harvest aflatoxin contamination in peanut Arachis hypogaea mechanisms genotypic variation fungal ecology and mitigation strategies

Aflatoxin contamination in peanuts (Arachis hypogaea L.), particularly in tropical and subtropical regions where high temperatures and humidity favor fungal growth of Aspergillus flavus and Aspergillus parasiticus, remains a persistent challenge that causes severe economic losses and significant health risks globally. Extensive studies have recognized that aflatoxin B1 (AFB1) is the most prevalent and toxic form among others, while effective mitigation strategies are limited by the complex interaction of host genotype, fungal ecology, and post-harvest management practices. The review synthesizes recent advances in understanding postharvest aflatoxin accumulation, emphasizing genotypic variation, biochemical resistance mechanisms, and storage conditions. The review further integrates knowledge on aflatoxin biosynthesis, fungal dispersal dynamics, and toxicological kinetics. Unlike previous research of aflatoxin contamination in peanuts, this review synthesizes evidence across disciplines to highlight three recurring themes. Genotypic resistance alone is not sufficient to reduce aflatoxin contamination, as its expression is highly dependent on storage conditions, which tightly regulate fungal growth and toxin biosynthesis. Inconsistencies in reported resistance are often due to failure to distinguish between pre-harvest and post-harvest contamination, while emerging biochemical evidence indicates that resistance is controlled by coordinated interactions among physical barriers, antifungal metabolites, and host–pathogen signaling pathways. An integrated management framework is proposed combining resistant genotypes, rapid air-drying to safe moisture limits (< 7–8%), and improved storage systems tailored to stakeholders. Key research gaps include standardized screening protocols, validation of resistance in multiple locations, and robust integration of breeding with post-harvest technologies to enable sustainable aflatoxin management.