Effect of Phosphorylation on the Structure and Emulsification Properties of Different Fish Scale Gelatins

Abstract

This study aimed to investigate the effect of phosphorylation on the structure and emulsification of Coregonus peled, Esox lucius and Grass carp scale gelatin. Fourier transform infrared spectroscopy (FTIR) and endogenous fluorescence spectra showed that the structures of the three fish scale gelatins changed. Additionally, the surface hydrophobicity index of the three fish scale gelatins increased by 36.72, 31.42 and 111.67, respectively, after 1 h of phosphorylation, and the surface tension decreased by 17.27, 32.58 and 18.7 mN/m, respectively. The emulsification activity index increased by 115.86, 155.22 and 45.52 m2/g, and the emulsification stability index increased by 98.37, 256.77 and 169.61 min, respectively. The structure of fish scale gelatin changed after phosphorylation, which resulted in the improvement of emulsification. This work will provide useful information to understand the relationship between the structure and function of gelatin.

The Structural and Functional Differences between Three Species of Fish Scale Gelatin and Pigskin Gelatin

“…Moreover, the reduced and non-reduced samples had similar structures, which indicates that there was no disulfide bond between the gelatin molecules. These phenomena are also similar to our previous research [ 19 ].…”

“…FG had the lowest solubility (89.47%); CPG had the highest solubility (94.19%); and the three kinds of FSG showed similar values. The better solubility of FSGs may be related to their lower subunit content and more exposed hydrophilic groups, which may promote the balance of hydrophobicity and hydrophilcity, as well as the hydratability of protein to water [ 19 , 30 ]. The low solubility of FG may be associated with low purity.…”

“…The FITR spectra of gelatin was analyzed according to the method described by Yang et al [ 19 ]. Gelatins and KBr were mixed in a ratio of 1:100 and pressed into thin slices.…”

“…The endogenous fluorescence spectroscopy of the gelatin solutions was analyzed according to the method described by Yang et al [ 19 ], with slight modification. Gelatins were dissolved in 10 mmol/L phosphate buffer solution with a pH of 7.0, and the test sample solution containing 0.2 mg/mL gelatin was prepared.…”

“…The surface hydrophobicity index of the gelatin solutions was measured according to the method described by Yang et al [ 19 ]. Briefly, the ammonium salt of 1- anilino -8-naphthalenesulfonate (ANS) was used as a fluorescent probe.…”