In vitro antifungal activity against Aspergillus niger was used to screen the lactic acid bacteria (LAB) isolated from whole wheat sourdough. Sequencing results of the PCR products led to the identification of Lactobacillus reuteri as the selected isolate. The LAB isolate had a proper anti-aflatoxigenic capability, and it reduced the amount of B1, B2, G1 and G2 aflatoxins, based on the results of HPLC analysis. n-Decanoic acid, 3-hydroxydecanoic acid and 3-hydroxydodecanoic acid were also identified as the bioactive ingredients using gas chromatography/mass spectrometry in the antifungal fraction obtained from preparative thin-layer chromatography of the L. reuteri culture filtrate. Furthermore, it was revealed that the sourdough fermented with the selected LAB isolate had a significant influence (P < 0.05) on the quality of the produced pan bread in terms of hardness, specific volume and phytic acid content. The growth of A. niger on the produced bread was also remarkably decreased using the controlled sourdough (containing the selected LAB isolate) in comparison with the spontaneous sourdough and control bread. Based on these findings, techno-functional properties of the selected LAB isolate were clarified, and therefore this isolate can be used successfully as a potent protective starter culture for sourdough bread processing.

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