Antimicrobial Activity of Echinophora platyloba Aqueous Extract on Gas- Producing Fungi in Doogh

Nowadays, the application of natural antimicrobials like plant extracts in food preservation isbecoming popular and increasing. The aim of this study is to determine the effect of Echinophora platyloba (E.platyloba) aqueous extract on gas-producing fungi and sensory properties of doogh. For this reason, theconcentration of 0% (Control), 0.125%, 0.25%, 0.5%, 1%, 2%, 4% and 8% of the extract were prepared. Fivesamples of doogh containing no preservatives or extract was purchased from manufacturer factories. Six types ofmold and ten types of yeast were isolated from the samples. The isolated fungi were cultured in the platescontaining different concentrations of E. platyloba aqueous extract. After determination of the effectiveconcentration of the extract, the sensory properties of samples were evaluated using five-point hedonic scale.The results showed that the E. platyloba extract have antifungal properties and its effect against the yeasts wasgreater than molds. At the extract concentration of 8%, the count of yeasts decreased to zero and the half of moldgrowth was inhibited. Due to the negative effect on sensory properties of doogh at the extract concentration of8%, it cannot be used as a preservative, but it might be applied as an aromatic or flavoring agent at lowerconcentrations in this product.