engleski

Influence of mycotoxin presence at harvest on naturally occurring phenolics and carotenoids during storage of maize grain produced in a dry and hot growing season

The objective of the present study was to determine the effect of plant growth location on mycotoxin formation in maize hybrids and to explore whether mycotoxin presence during grain development could affect contents of naturally occurring phenolics and carotenoids after one year of storage. Grain from five maize hybrids was produced at two locations ; climate at both locations was dry and hot, however, location 1 had light soil nearby river compared to the heavy soil of location 2. The presence of yeast and fungi (Penicillium, Aspergillus, Fusarium, Cladosporium, and Mucor) was detected while the content of mycotoxins aflatoxin B1, ochratoxin A, zearalenone, deoxynivalenol, fumonisin and T-2 toxin was determined. Free, bound and total phenolics, as well as total carotenoids were determined in grain samples after harvest and after one year of storage. Location 2 was less favourable for maize grain production when compared to location 1 (6.10 vs. 9.50 t/ha of yield), which was accompanied by the presence of more fungal species, a higher number of total yeast and mould colonies, and higher total carotenoid content (P<0.001). Furthermore, there was a greater decrease during storage in contents of total phenolics and carotenoids in grain from location 2. Similar free and bound phenolics content between locations after harvest altered to the higher free and lower bound phenolics in grain produced at location 2 after one year of storage (P<0.001). Defence system produced more carotenoids in mouldy grain from location 2 during plant growth, and subsequent decrease in carotenoids and phenolics suggests that these compounds may have some protective effect during storage. Although the mechanisms of action are yet to be revealed, results from the present study show that one of the potential strategies for minimizing mycotoxin appearance could be increasing the content of antioxidants naturally occurring in maize grain.

maize; mycotoxins; carotenoids; phenolics

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