title: Associative and segregative phase separations of gelatin/kappa-carrageenan aqueous mixtures.
abstract: The effects of ionic strength, temperature, and pH on the phase separation behavior of type B pigskin gelatin/sodium-type kappa-carrageenan aqueous mixtures were investigated. Depending on the different combinations of temperature and sodium chloride (NaCl) concentration, the mixtures showed compatible, associative, and segregative phase separation behaviors. Additionally, a coexistence of associative and segregative (associative-co-segregative) phase separations was expected at low temperature and low NaCl concentration. These different phase separation events were observed using confocal scanning laser microscopy. Moreover, it was found that the segregative phase separation when alone is induced by the ordering of kappa-carrageenan chains, while that in the coexistence region is induced by the ordering of gelatin chains. pH had a significant effect on the associative phase separation, resulting in morphologies changing from compatible solution to liquid coacervate and further to solid precipitate with decreasing pH. These were attributed to the dramatic changes of the charge density of amphoteric gelatin during the pH decrease.
authors.affiliation: Unilever Food and Health Research Institute, Olivier van Noortlaan 120, 3133AT Vlaardingen, The Netherlands. Yapeng.Fang@Unilever.com
authors.forename: Yapeng
authors.initials: Y
authors.lastname: Fang
authors.forename: Liangbin
authors.initials: L
authors.lastname: Li
authors.forename: Chiharu
authors.initials: C
authors.lastname: Inoue
authors.forename: Leif
authors.initials: L
authors.lastname: Lundin
authors.forename: Ingrid
authors.initials: I
authors.lastname: Appelqvist
mesh_terms: D002351:Carrageenan / Q000737:chemistry*; D045424:Complex Mixtures / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D017186:Titrimetry
chemical_list: D045424:Complex Mixtures; D012996:Solutions; D012965:Sodium Chloride; D002351:Carrageenan; D005780:Gelatin