title: First assessment of diffusion coefficients in model cheese by fluorescence recovery after photobleaching (FRAP).
abstract: Mass transfer of solutes like salt, moisture and metabolites, is very important for the final quality of cheese, through the control of the brining and ripening processes. Numerous studies have reported salt and water transfer properties in cheese, but few have dealt with other solutes. Moreover, most diffusion coefficients have been obtained by macroscopic and destructive methods. We developed the fluorescence recovery after photobleaching (FRAP) technique on a confocal microscope to measure in situ and at the microscopic scale diffusion properties inside cheese. A model matrix based on ultrafiltrated milk was used. FITC-dextran molecules were chosen as models of migrant solutes. Diffusion coefficients were estimated with a modelling approach which takes into account diffusion during the bleach phase. The FITC-dextrans (4 and 20 kDa) were able to migrate in the proteinic network, but their mobility was 2.2-3 times lower than in water, depending on their size.
authors: INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, F-35042 Rennes, France; Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'Oeuf, F-35042 Rennes, France; Université Européenne de Bretagne, F-35000 Rennes, France. Electronic address: Juliane.Floury@agrocampus-ouest.fr.
authors: J
authors: J
authors: Floury
authors: INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, F-35042 Rennes, France; Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'Oeuf, F-35042 Rennes, France.
authors: M-N
authors: MN
authors: Madec
authors: Cell and Tissue Imaging Facility (PICT-IBiSA), CNRS - Institut Curie, Centre de Recherche, Paris, France.
authors: F
authors: F
authors: Waharte
authors: INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, F-35042 Rennes, France; Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'Oeuf, F-35042 Rennes, France.
authors: S
authors: S
authors: Jeanson
authors: INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, F-35042 Rennes, France; Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'Oeuf, F-35042 Rennes, France.
authors: S
authors: S
authors: Lortal
mesh_terms: D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D003911:Dextrans / Q000737:chemistry; D004058:Diffusion; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry; D036681:Fluorescence Recovery After Photobleaching / Q000379:methods; D007700:Kinetics; D008892:Milk / Q000737:chemistry*; D008962:Models, Theoretical; D012996:Solutions / Q000737:chemistry
chemical_list: D003911:Dextrans; D012996:Solutions; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate
keywords: Cheese; Confocal microscopy; Diffusion; FRAP