References of "Detry, Jean G"
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See detailPossible Influence of Surfactants and Proteins on the Efficiency of Contact Agar Microbiological Surface Sampling
Deckers, Sylvie M.; Sindic, Marianne ULg; Anceau, Christine ULg et al

in Journal of Food Protection (2010), 73(11), 2116-2122

Agar contact microbiological sampling techniques, based on a transfer of the microorganisms present on a surface to a culture medium, are widely used to assess and control surface cleanliness and to ... [more ▼]

Agar contact microbiological sampling techniques, based on a transfer of the microorganisms present on a surface to a culture medium, are widely used to assess and control surface cleanliness and to evaluate microbial contamination levels. The effectiveness of these techniques depends on many environmental parameters that influence the strength of attachment of the bacteria to the surface. In the present study, stainless steel and high density polyethylene surfaces were inoculated with known concentrations of Staphylococcus epidermidis. Following an experimental design, the surfaces were sampled with different types of replicate organism direct agar contact plates and Petrifilm; results indicated that recovery rates were influenced by the presence of egg white albumin or Tween 80 in the inoculum solutions or by the introduction of surfactants into the contact agar of the microbiological sampling techniques. The techniques yielded significantly different results, depending on sampling conditions, underlining the need for a standardization of laboratory experiments to allow relevant comparisons of such techniques. [less ▲]

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See detailFlow rate dependency of critical wall shear stress in a radial-flow cell
Detry, Jean G; Jensen, Bo Boye Busk; Sindic, Marianne ULg et al

in Journal of Food Engineering (2009), 92(1), 86-99

In the present work, a radial-flow cell was used to study the removal of starch particle aggregates from several solid substrates (glass, stainless steel, polystyrene and PTFE) in order to determine the ... [more ▼]

In the present work, a radial-flow cell was used to study the removal of starch particle aggregates from several solid substrates (glass, stainless steel, polystyrene and PTFE) in order to determine the critical wall shear stress value for each case. The particle aggregates were formed by aspersion of a water or ethanol suspension of starch granules on the surfaces. Depending on the substrate and on the suspending liquid, the aggregates differed in size and shape. Aggregate removal was studied at two flow rates. At the lower flow rate (Re-inlet = 955), the values of critical wall shear stress for the different surfaces suggested that capillary forces were, for all of them, playing an important role in aggregate adhesion since aqueous based aggregates were always more difficult to remove. At the higher flow rate (Re-inlet = 2016) the critical wall shear stress increased as a result of the change in the flow pattern in the vicinity of the aggregates and not because of changes in the type of particle adhesion. This raises the importance of the experimental conditions on assessing the critical wall shear stress since this parameter may not be always only directly related to the soil adhesion strength. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailCleanability assessment of model solid surfaces with a radial-flow cell
Detry, Jean G; Rouxhet, Paul G; Boulange-Petermann, Laurence et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2007), 302(1-3), 540-548

The cleanability of several model solid substrates (glass, stainless steel, polystyrene and polytetrafluoroethylene-PTFE) was studied with a radial-flow cell. Two soiling methods were used to mimic ... [more ▼]

The cleanability of several model solid substrates (glass, stainless steel, polystyrene and polytetrafluoroethylene-PTFE) was studied with a radial-flow cell. Two soiling methods were used to mimic splashing with oil; a thin layer chromatography sprayer giving a narrower and more reproducible oil droplet size distribution was preferred. Glass was the most cleanable substrate, a result which may be consistent with the presence of a swelling gel-like layer at the surface. For the other substrates, the mechanical action exerted by the fluid played a major role in oil removal; however the detergent seemed to intervene after about 5-10 min, facilitating cleaning of PTFE. Oil droplet removal took place only at high wall shear stress, in zones where flow conditions where not well controlled making it impossible to evaluate the wall shear stresses needed for oil droplet removal. Evaluation of cleanability by using the radial-flow cell is restricted to variations of wall shear stresses in a range below 3 N m(-2). (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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