title: Influence of internal composition on physicochemical properties of alginate aqueous-core capsules.
abstract: OBJECTIVE
  To enhance physicochemical properties of alginate aqueous-core capsules, conventional strategies were focused in literature on designing composite and coated capsules. In the present study, own effect of liquid-core composition on mechanical and release properties was investigated.
  
  
  METHODS
  Capsules were prepared by dripping a CaCl2 solution into an alginate gelling solution. Viscosity of CaCl2 solution was adjusted by adding cationic, anionic and non-ionic naturally derived polymers, respectively chitosan, xanthan gum and guar gum. In parallel, uniform alginate hydrogels were prepared by different methods (pouring, in situ forming and mixing). Mechanical stability of capsules and plane hydrogels were respectively evaluated by compression experiments and small amplitude oscillatory shear rheology and then correlated. Capsules permeability was evaluated by monitoring diffusion of encapsulated cochineal dye, riboflavin and BSA. The core-shell interactions were investigated by ATR-FTIR.
  
  
  RESULTS
  Results showed that inner polymer had an impact on membrane stability and could act as an internal coating or provide mechanical reinforcement. Mechanical properties of alginate capsules were in a good agreement with rheological behavior of plane hydrogels. Release behavior of the entrapped molecules changed considerably. This study demonstrated the importance of aqueous-core composition, and gave new insights for possible adjusting of microcapsules physicochemical properties by modulating core-shell interactions.
authors.affiliation: Université de Lorraine, LIBio, ENSAIA, 2 avenue de la Forêt de Haye, TSA 40602, F-54505 Vandœuvre-lès-Nancy, France. Electronic address: ghazi.ben-messaoud@univ-lorraine.fr.
authors.forename: Ghazi
authors.initials: G
authors.lastname: Ben Messaoud
authors.affiliation: Université de Lorraine, LIBio, ENSAIA, 2 avenue de la Forêt de Haye, TSA 40602, F-54505 Vandœuvre-lès-Nancy, France. Electronic address: laura.sanchez-gonzalez@univ-lorraine.fr.
authors.forename: Laura
authors.initials: L
authors.lastname: Sánchez-González
authors.affiliation: Cookal Company, 21 avenue de la Meurthe, 54320 Maxéville, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Probst
authors.affiliation: Université de Lorraine, LIBio, ENSAIA, 2 avenue de la Forêt de Haye, TSA 40602, F-54505 Vandœuvre-lès-Nancy, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Desobry
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002122:Calcium Chloride / Q000737:chemistry; D002214:Capsules / Q000737:chemistry; D002627:Chemistry, Physical; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D002214:Capsules; D006603:Hexuronic Acids; D014867:Water; D020723:Glucuronic Acid; D002122:Calcium Chloride
keywords: Chitosan; Guar gum; Mechanical stability; Release behavior; Rheological characterization; Xanthan gum