Influence of Using Different Drying Technique on the Level of Toxigenic Aspergillus flavus in Maize (Zea mays) Seeds

Abstract

Deterioration of maize is mainly affected by moisture content, temperature, relative humidity, storage conditions period of drying and method, fungal growth, and insect pests. The growth of Aspergillus flavus in maize is facilitated by hot and humid conditions and they pose a major risk through production of mycotoxins. To maintain high-quality maize for both short- and long-term storage, maize must be protected from weather, growth of microorganisms, and pests. The Influence of drying on the toxigenic Aspergillus flavus level of maize seeds was investigated. Different drying method used are; constructed wooden solar dryer lined with aluminum foil, constructed wooden solar dryer lined with black polythene, calabash (Crescentia cujete), tray lined with plantain (Musa paradisiaca) leaf, tray lined with Thaumatococcus daniellii leaf. ] Maize seeds were inoculated with spore suspension of toxigenic Aspergillus flavus.  The inoculated maize seeds were dried using different drying methods provided and the growth performance of the A. flavus was monitored on inoculating chamber with the spores counted at weekly interval.  After three days  of drying, inoculated maize grains dried with wooden solar dryer lined with aluminum foil  and calabash were found to have the lowest spore levels of Aspergillus flavus counted with haemocytometer counting chamber (5.50x105 sfu/l and 9.50 x105 sfu/ml) as compared to the value of spores counted from the other drying method used. There was a continuous decrease in the values of moisture content in all the samples from day 1 to day 3. The highest reduction was also observed in samples of solar dryer lined with aluminum foil. Considering the different materials used for drying maize in this study,  Calabash and solar dryer lined with aluminum foil prove  to be more reliable and efficient in reducing the sporulation level of A. flavus