Abstract

CARO VELEZ, Carlos Andrés  and  LEON PELAEZ, Ángela M. FUNGAL GROWTH INHIBITION OF Aspergillus ochraceus WITH "PANELA"FERMENTED WITH WATER KEFIR GRAINS. Vitae [online]. 2014, vol.21, n.3, pp.191-200. ISSN 0121-4004.

Background: Water kefir (WK) is a drink, from sugary solutions fermented with kefir grains, which contain lactic acid bacteria (LAB) and yeasts. A. ochraceus is a mycotoxigenic filamentous mold that contaminates and produces ochratoxin in coffee grains, grapes and wine. The antifungal activity of LAB fermented products has been studied, but there is no evidence yet of the antifungal activity of WK. Objectives: The objective of this work was to assess the inhibitory power of the panela solutions fermented with WK at different times and temperatures on Aspergillus ochraceus. Methods: 10 μL of a solution containing 3x10⁷ conidia.ml^-1 of A. ochraceus were inoculated in malt extract agar, mixed with cell free supernatants (CFS), obtained from the fermented products, incubated at 25°C and taking four daily mycelium diameter measures, in order to calculate the growth rate and Lag phase. The organic acids (OA) concentration in the CFS was determined by HPLC. Results: The CFS fermented for a longer time and higher temperature than the others presented the upper concentration of OA, and also the main decrease of the pH, being the CFS8 (pH: 2.8) the most inhibitory. Conclusions: The Panela solution was suitable for the fermentation with WK, obtaining metabolites like organic acids with antifungal properties.

Keywords : Kefir; organic acids; antifungal; Aspergillus ochraceus.

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