2018 (05) :«Assessment of the potential and innovative ways of using plant-based antimicrobial phenolic compounds for food preservation.» (thesis by Lynda BOUARAB CHIBANE)

Thesis defended on 05/28/2018

Thesis direction:


Dr Nadia OULAHAL, Pr Pascal DEGRAEVE

Funding:


National Research Agency (ANR, Actiphen Project)

Partners:

  •     Nat'ex Biotech (Toulouse, 31),
  •     Sté Addikem (St-Pal-de-Mons, 43),
  •     Alimentec Innovative Technological Platform (ITP): Packaging and Food, Quality, safety, perception and sustainable development,
  •     UMR CNRS University Paul Sabatier IMRCP (Molecular Interactions and Chemical and Photochemical Reactivity, Toulouse),
  •     UMR CNRS-Université Lyon 1 ISA (Institute of Analytical Sciences, Lyon)

 

Doctoral school :


EDISS (Interdisciplinary Doctoral School for Health Sciences), ED n ° 405, Université Claude Bernard Lyon 1

Summary:

The plant kingdom is a renewable resource for a wide range of biologically active secondary metabolites. This thesis work proposes a multidisciplinary strategy for evaluating the potential of phenolic antimicrobial compounds of plant origin for food preservation. A screening of antimicrobial activity in vitro against 8 strains of pathogenic flora and food alteration of a hundred pure molecules and sixty plant extracts first made it possible to select the most assets. Different mechanisms of action vis-à-vis S. aureus could be demonstrated by flow cytometry coupled with the use of markers of the physiological state of bacteria for some of the active compounds selected. With a view to application to beef, the antibacterial activity of the most active phenolic compounds or plant extracts has been reassessed in more complex culture media mimicking their protein and fat content. The results of this screening and a microbiological monitoring of ground beef with 1% (m / m) of added extract made it possible to observe that the losses of antibacterial activity observed were notably correlated to the interactions of phenolic compounds with proteins, or fat. The incorporation of phenolic compounds or plant extracts in packaging materials in contact with food was the second route of implementation envisaged. Plastic films retaining antibacterial activity have thus been produced.