title: Elucidation of aqueous interactions between fish gelatin and sodium alginate.
abstract: The interactions between fish gelatin (FG) and sodium alginate (AL) in aqueous solutions were investigated at 25°C by turbidimetric acid titration, zeta potentiometry, dynamic light scattering, methylene blue spectrophotometry, confocal microscopy, and three types of state diagram. FG formed solid-state insoluble complexes, i.e., precipitates, with AL, mainly by electrostatic attractions; the complex formation was significantly influenced by pH, FG-to-AL weight ratio, total biopolymer concentration (CT), and ionic strength. The insoluble complexes formed below a boundary pH (pHφ1) underwent continuous aggregation during acid titration, until immediate visible precipitation occurred at another boundary pH (pHp). The formation and aggregation of insoluble complexes were facilitated by increasing CT or adding small amounts of NaCl, but were greatly suppressed in the presence of high NaCl concentration. The insoluble complexes were formed reversibly depending on pH and transformed to a coupled gel network after 24h incubation, depending on pH, CT, and ionic strength.
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea.
authors.forename: Md Abdur
authors.initials: MA
authors.lastname: Razzak
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea; Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea.
authors.forename: Moojoong
authors.initials: M
authors.lastname: Kim
authors.affiliation: Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea; Graduate School of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea. Electronic address: dchung@snu.ac.kr.
authors.forename: Donghwa
authors.initials: D
authors.lastname: Chung
keywords: Alginate; Complexes; Fish gelatin; Interactions; Precipitation