title: An optimized methodology to analyze biopolymer capsules by environmental scanning electron microscopy.
abstract: The aim of this paper is to describe an optimized methodology to study the surface characteristics and internal structure of biopolymer capsules using scanning electron microscopy (SEM) in environmental mode. The main advantage of this methodology is that no preparation is required and, significantly, no metallic coverage is deposited on the surface of the specimen, thus preserving the original capsule shape and its surface morphology. This avoids introducing preparation artefacts which could modify the capsule surface and mask information concerning important feature like porosities or roughness. Using this method gelatin and mainly fatty coatings, difficult to be analyzed by standard SEM technique, unambiguously show fine details of their surface morphology without damage. Furthermore, chemical contrast is preserved in backscattered electron images of unprepared samples, allowing visualizing the internal organization of the capsule, the quality of the envelope, etc... This study provides pointers on how to obtain optimal conditions for the analysis of biological or sensitive material, as this is not always studied using appropriate techniques. A reliable evaluation of the parameters used in capsule elaboration for research and industrial applications, as well as that of capsule functionality is provided by this methodology, which is essential for the technological progress in this domain.
authors.affiliation: LaSIE UMR 7356 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle, France. Electronic address: egle.conforto@univ-lr.fr.
authors.forename: Egle
authors.initials: E
authors.lastname: Conforto
authors.affiliation: Equipe Approches Moléculaires Environnement-Santé, LIENSs, UMR 7266 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Joguet
authors.affiliation: INNOV'IA, 4 rue Samuel Champlain, Z.I. Chef de Baie, 17000 La Rochelle, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Buisson
authors.affiliation: IDCAPS, filiale R&D INNOV'IA, 4 rue Samuel Champlain, Z.I. Chef de Baie, 17000 La Rochelle, France.
authors.forename: Jean-Eudes
authors.initials: JE
authors.lastname: Vendeville
authors.affiliation: IDCAPS, filiale R&D INNOV'IA, 4 rue Samuel Champlain, Z.I. Chef de Baie, 17000 La Rochelle, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Chaigneau
authors.affiliation: Equipe Approches Moléculaires Environnement-Santé, LIENSs, UMR 7266 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Maugard
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D002214:Capsules / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods
chemical_list: D001704:Biopolymers; D002214:Capsules; D005780:Gelatin
keywords: Backscattered electrons; Biopolymer; Capsules; Coating; Encapsulation; Environmental mode; Scanning electron microscopy