Kernel structure and varietal attributes determine aflatoxin production by Aspergillus flavus in maize (Zea mays L.).

Maize (Zea mays L.) is a globally significant crop that is susceptible to contamination by aflatoxigenic fungi during storage. Aspergillus flavus produces aflatoxins, which are toxic and carcinogenic, posing substantial food safety risks, particularly in regions where maize is a dietary staple. Due to the chemical stability of aflatoxins, early prevention of contamination is essential. This study evaluated five maize varieties (blue, purple, yellow, white Bajío, and white Sinaloa) to determine whether their physical and chemical grain characteristics or antioxidant content influence aflatoxin production under storage-like conditions. Maize kernels were inoculated with A. flavus and maintained under controlled storage conditions. Total aflatoxin levels were quantified, and grain properties, including thousand-kernel weight, flotation index, and texture, as well as total phenolic content and antioxidant activity, were analysed. Pearson correlation and path analysis indicated that physical traits associated with density, starch content, and hardness significantly influenced aflatoxin accumulation, whereas antioxidant content did not. These findings demonstrate that the structural and physical properties of maize kernels are more critical than antioxidant content in limiting fungal growth and aflatoxin production during storage. Selecting maize varieties with robust physical grain traits may reduce the risk of aflatoxin contamination during storage.