Multiple fluorescence labelling of proteins, lipids and whey in dairy products using confocal microscopy

Abstract

Texture optimisation of dairy products is a major aim for manufacturers. A better knowledge of the structure and spatial organisation of their main components would allow the optimisation of their texture. In this study, using confocal scanning laser microscopy, a multiple fluorescent labelling of proteins, lipids and whey was developed to visualise these main components simultaneously in dairy products. Different extrinsic fluorescent probes were tested by confocal microscopy and fluorescence spectroscopy. Fuchsin acid, Bodipy® 665/676 and DM-NERF were selected to label proteins, lipids and whey, respectively. Methods for selecting stable and specific fluorescent probes and for obtaining the multiple fluorescent labelling are presented. An application example on a dairy gel is also shown. © Inra/Elsevier, Paris.