A Comprehensive Study on the Occurrence of Mycotoxins and Their Producing Fungi during the Maize Production Cycle in Spain

Abstract

Mycotoxin contamination is one of the main problems affecting corn production, due to its significant risk to human and animal health. The Fusarium and Aspergillus species are the main producers of mycotoxins in maize, infecting both pre-harvest and during storage. In this work, we evaluated the presence of mycotoxins and their producing species along maize production cycles in three different stages (anthesis, harvest, and storage) during three consecutive seasons (2016–2018). Fungal occurrences were studied using species-specific PCR protocols, whereas mycotoxin levels were determined by LC-MS/MS. Fumonisin-producing Fusarium species (F. verticillioides and F. proliferatum), as well as the aflatoxin producer Aspergillus flavus, were the most predominant species at all stages; although, during some seasons, the presence of F. graminearum and A. niger aggregate species were also identified. Contrastingly, fumonisins were the only mycotoxins detected and levels were always under legal regulations. The results presented here demonstrate that even when fungal contamination occurs at the early stages of the maize production cycle, the application of good agricultural and storage practices might be crucial to ensure mycotoxin-free grains.

La contaminación por micotoxinas es uno de los principales problemas que afectan a la producción de maíz, debido a su importante riesgo para la salud humana y animal. En este trabajo, evaluamos la presencia de micotoxinas y sus especies productoras a lo largo de todo el ciclo de producción del maíz (antesis, cosecha y almacenamiento) durante tres temporadas consecutivas (2016-2018). Las especies de Fusarium productoras de fumonisina (F. verticillioides y F. proliferatum), así como el productor de aflatoxinas Aspergillus flavus, fueron las especies predominantes en todas las etapas. Las únicas micotoxinas que detectamos fueron las micotoxinas y en todos los casos se encontraban por debajo de los límites legislados. Los resultados obtenidos demuestran que incluso cuando la contaminación por hongos se produce desde las primeras etapas del ciclo de producción del maíz, la aplicación de buenas prácticas agrícolas y de almacenamiento podrían ser cruciales para asegurar granos libres de micotoxinas.