21 Jun 2016

The FooD-STA Webinar "How can we better evaluate the efficiency of food antimicrobials?" took place Jun 21, 2016 4:00 PM CEST.

The pdf-version of the presentation is attached below and you can view the recording at the bottom of this page.

Abstract: Food antimicrobials may be defined as chemical compounds present or added in foods or in food processing environments that inhibit the growth of undesirable microorganisms or inactivate them. In order to optimize the use of food antimicrobials, their effectiveness has to be accurately evaluated.
For food preservatives, Minimum Inhibitory Concentrations (MIC) determination is the most common way to evaluate the inhibitory efficiency, using agar diffusion or broth dilution methods. The latter can easily be improved by a simple modeling approach based on mathematical analyses of growth curves. A accurate value of MIC can be obtained with a confidence interval, together with a added value, the Non Inhibitory Concentration (the concentration below which the antimicrobial agent has no inhibitory effect). The accurate determination of these two values help in adjusting concentrations of preservatives in foods and optimizing their efficiency, in particular in the case of combinations. The effectiveness of biocides used in food processing environments is generally evaluated by determination of Minimal Bactericidal Concentration (MBC) (obtention of a certain log reduction of the population: 4-log, 5-log). Most of the time, this evaluation is done by plate counting after challenging planktonic cells or sometimes biofilms with selected concentrations. New perspectives exist using confocal laser scanning microscopy: dynamics of antimicrobial action can give informations on bacterial resistance within in–situ biofilm structures.
The objectives of this webinar are to help food companies to optimize the use of antimicrobials in their products or in their manufacturing environment by i) better characterizing the antimicrobial activity as preservatives and iii) use rapid methods to evaluate antimicrobial activity in biofilm structures.

The presenter, Florence Dubois-Brissonnet, Ph.D., is professor of microbiology and food safety at the Department of Food Science and Technology at AgroParisTech, France.