Abstract:

The objective of this work was to assay the influence of different fermentation types (yeast fermentation and lactic
acid fermentation) on antioxidant activity and total polyphenol content in selected cereals. After fermented by Lactobacillus
delbrueckii, Saccharomyces cerevisiae or nothing, the cereals were extracted by ethanol. The content of total polyphenols
in extracts was determined by the Folin-Ciocalteu method, and the antioxidant activity was measured by 1,1-diphenyl-2-
picrylhydrazyl (DPPH) radical scavenging assay, ferric reducing-antioxidant power (FRAP) method and thiobarbituric acid
(TBA) test. This study indicated that four cereals used widely for human consumption exhibited significant levels of free
radical scavenging activity, ferric-reducing power, inhibitory activity against lipid peroxidation and total polyphenol content.
These factors suggested that cereal-based foods alone could contain important dietary antioxidants, but further research is
needed to determine whether or not these dietary antioxidants could be beneficial to human health. The total polyphenol
content (TPC) increased upon fermentation. The presence of these microorganisms was more or less important for enhanced
levels of antioxidant activity. Thus fermentation offers a tool to further increase the bioactive potential of cereal products.
In conclusion, it seems advantageous to select microorganism starter culture for the fermentation of cereals based on their
positive correlation with total antioxidant capacity.

Key words: fermentation, cereal extracts, total polyphenol, antioxidant