Rheological properties and structure modification in liquid and gel of tilapia skin gelatin by the addition of low acyl gellan. (May 2019)

• Record Type: Journal Article
• Authors: Sow, Li Cheng; Tan, Si Jia; Yang, Hongshun
• Is Part Of: Food hydrocolloids. Volume 90(2019)
• Page Start: 9
• Page End: 18
• Publication Date: 2019-05
• Subjects: Fish gelatin -- Confocal laser scanning microscopy -- Rheology -- Microstructure -- Texture -- Polysaccharide; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2018.12.006
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: Fish gelatin (FG) was modified by low acyl gellan (Ge) to produce a replacer for pork gelatin (PG). Increasing mixing ratio of Ge:FG (w/w) modified rheological properties and structure of FG progressively. The largest of FG-Ge complex coacervates (1775 ± 593 nm) formed at Ge:FG (w/w) of 7.5:92.5, driven by electrostatic interaction between FG and Ge. However, the network density was reduced by the formation of large complex coacervates (fractal dimension, df 2.45 ± 0.01 in FG-Ge vs. 2.48 ± 0.00 in FG). The non-interacting FG re-associated to a greater extent into triple helix (helix/coil ratio, 3.10 ± 0.93 in FG-Ge vs. 0.58 ± 0.07 in FG), therefore increased the rigidity of the gel. The mixed gel was stronger and more stable, with lower compliances (J0, J m 1 ) and a higher melting temperature (Tm ) than FG. The mixed gel at a Ge:FG (w/w) of 1:99 had similar rheological properties to PG. A schematic model was proposed to illustrate the progressive modification of FG by Ge. Graphical abstract: Image 1 Highlights: Fish gelatin (FG) and gellan (Ge) were combined to mimic pork gelatin (PG). The Winter-Chambon law applied to the gelling mechanism of FG-Ge. Burger's model was used for creep-recovery characterisation of FG-Ge gel. A gel at a Ge:FG of 1:99 had similar rheological properties to PG. At Ge:FG ≥ 2.5:97.5, a bi-continuous gel formed with Ge as the continuous phase.