Swelling kinetics and cross-linking stability of gelatins with different gel strength

The purpose of this study was to investigate swelling kinetics and stability of gelatins with different gel strengths，as well as the component which might affect gel strength and cross-linking reactivity.SDS-PAGE assay was undertaken to determine the content of gelatin components - α，β and γ component which were isolated through CM52 cation exchange column ，and the cross-linking activity of the components was determined by the formaldehyde cross-linking simulation study.At the same time，the equilibrium swelling ratio (S_eq) and ε-amino acid residue content indicative of the swelling kinetics and the stability of cross-linking were assessed according to the methods reported in the literatures.It was shown that the increase in α- component led to the corresponding increase in the gel strength of gelatin but the decrease in the equilibrium swelling ratio.The ε-amino acid residue contents of α，β and γ components decreased in the order of α> β> γ.It was found that the gel strength increased as the ε-amino acid content did .Accelerating study showed that instability-indicative cross-linking could occour in the gelatin with higher gel strength during storage.