Gelation of fish gelatin studied by multi-particle tracking method

Gelatin from various sources are extensively used as food hydrocolloids. Recently, fish gelatin has attracted special attention because of religious or medical reasons. Most food gels show structural inhomogeneity that may affect their texture and flavor release, although gelatin gels appear transparent and homogeneous. In this study, the local dynamics at the micron scale of the fish gelatin were investigated by using a multiple particle tracking method. The slow gelation of the fish gelatin compared to mammalian gelatin enabled us to study the gelation process in detail. The dynamics of microspheres embedded in the gelatin revealed the transition of gelatin from a homogeneous fluid to an elastic gel that is rheologically inhomogeneous at the micron scale. [Display omitted] •Slow gelation of the fish gelatin was studied by multiple particle tracking method.•Gelatin behaved as homogeneous fluid in the initial stage.•Gelatin exhibited rheological inhomogeneity in the gel state.