Phosphorylation modification on functional and structural properties of fish gelatin: The effects of phosphate contents

The gel, rheological and structural properties of fish gelatin (FG) were investigated through phosphorylation with different ratios of sodium pyrophosphate (TSPP) (FG:TSPP = 40:0, 40:1, 40:2, 40:4, and 40:6). It showed that phosphorylation modification significantly increased gel strength, textural properties, emulsification, and emulsification stability of FG. The surface hydrophobicity and intrinsic fluorescence of phosphorylated FG were also significantly increased. Rheological results revealed that the apparent viscosity, melt/gel points, and gel strength of FG were increased by phosphorylation with TSPP, but shortened the gelation time. Low field nuclear magnetic resonance (LF-NMR) showed that phosphorylation reduced mobility of water in FG. FTIR results indicated that phosphorylation increased the beta-sheet/beta-turn contents but reduced the random coil contents. This study might provide a new guideline for the exploration of TSPP phosphorylation increased the functional properties of FG.

Automated summary

The gel, rheological and structural properties of fish gelatin (FG) were significantly improved through phosphorylation modification. Phosphorylation increased the gel strength, textural properties, emulsification, and emulsification stability of FG, as well as the surface hydrophobicity and intrinsic fluorescence. Phosphorylation with TSPP increased the apparent viscosity, melt/gel points, and gel strength of FG, while shortened the gelation time. Furthermore, it reduced the mobility of water in FG and altered its structural characteristics.