Effect of some Bioagents, Plant Extracts and Gamma Irradiation on the Deterioration and Fumonisin Production in Stored Maize Grains

Kararah, Mohamed A.; Abada, Khairy A.; Mohamed, Hisham A.; Taif, Yasser N.

doi:10.21608/ejp.2011.230023

Effect of some Bioagents, Plant Extracts and Gamma Irradiation on the Deterioration and Fumonisin Production in Stored Maize Grains

Document Type : Original Article

Authors

¹ Plant Pathology Department, Faculty of Agriculture, Cairo University, Giza 12612, Egypt

² Plant Pathology Research Institute, Agricultural Research Center, 12619, Giza, Egypt.

³ Ministry of Higher Education, Faculty of Agriculture, Republic of Yemen.

10.21608/ejp.2011.230023

Abstract

Public concern regarding food safety has increased in recent years as mycotoxins have been reported hazards associated with animal feeds in storage. Fusarium verticillioides contamination in food grains has been reported worldwide. This fungus produces fumonisins, that harmful to humans and animals.
Three strains of Trichoderma spp., i.e., T. viride, T. harzianum and T. hamatum, plant extracts of halfa barr and thyme as well as different gamma irradiation at doses were tested for their capability to decrease deterioration and fumonisins accumulation in stored maize grains. In vitro evaluation of the antagonistic effect of Trichoderma spp. against F. verticillioides revealed that T. viride was the most effective one in reducing the pathogen growth. When they formulated as a powder to study their effect on inhibiting fumonisins toxins produced in artificially inoculated maize grains during storage at 30°C and 90% relative humidity (RH) for up to 4 months, obtained results revealed that T. viride recorded the highest reduction in the frequency of F. verticillioides and toxin production during the tested storage period.
Application of different concentrations of n-hexane and chloroform – methanol and/or aqueous extracts of halfa barr and thyme caused significant reduction in the in vitro growth of F. verticillioides. n-hexane and chloroform - methanol (2:1 v/v) were more effective than the aqueous extracts of the halfa barr and thyme, respectively. Haifa barr extract at 4000 ppm caused the highest reduction to the fungal growth followed by thyme extract. Moreover, treatment of maize grains with halfa barr extract before storing for up to 4 months greatly reduced the population of F. verticillioides as well as fumonisins production.
Physical treatment of maize grains with different doses of gamma irradiation effectively reduced the incidence of F. verticillioides during storage for up to 4 months. Also, in case of artificial inoculation, these treatments greatly reduced fumonisins production in comparison with un-irradiated grains. The highest effect of irradiation was occurred by I0 kGy, which resulted in negligible incidence of F. verticillioides and complete inhibition of fumonisins production during the storage period.

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