Influence of storage period on occurrence and distribution of aflatoxins and fungi in maize kernels

Abstract

This study had two major objectives: 1) to investigate the influence of a seven-month storage period on maize contamination with aflatoxins (AFs) and 2) to examine the distribution of total count of fungi (TCF), A. flavus and aflatoxin B1 (AFB1) in the stored maize kernels. In the first part of this survey, 700 maize samples were collected in the period from October 2012 to April 2013. Presence of AFs was detected in 72% of maize, before entering the silos. The survey results indicated that the percentage of contaminated maize samples as well as the distribution of determined AFs concentrations changed during the storage period of seven months. By the prolongation of storage period, the percentage of non-contaminated maize samples decreased from 28% to 16%, while the percentage of contaminated samples in the concentration range 20-50 µg/kg increased from 18% to 25%. In the second part of this study, 32 maize samples from four different silos were analysed. The results showed that TCF, A. flavus and AFB1 were unevenly distributed. According to Duncan's multiple range test, in each silo, statistically significant differences (p<0.05) were noted for all tested parameters. Furthermore, within each silo, statistically significant correlation (r=0.76 at p<0.05) between the number of A. flavus colonies and AFB1 concentrations were observed. According to the obtained results and taking into account the trends in climatic changes in Serbia, further improvement in maize management system concerning AFs is warranted. The findings of this study could be of great importance to increase the knowledge related to the AFs management strategies in Serbia as well as in neighboring countries.

Keywords

• maize kernels
• storage
• silo
• aflatoxins
• aspergillus flavus
• total count of fungi