Physicochemical properties of giant salamander skin gelatin (GSSG) prepared at 45, 50, 55, 60, 65 °C were studied in comparison with those of tiger puffer skin gelatin (TPSG) and commercial bovine gelatin (CBG). It is showed that GSSG contained lower content of imino acid (179–181 residues/1000) than CBG (204 residues/1000) and TPSG (188 residues/1000). GSSG45 exhibited a protein pattern with α1- and β-chain, which attenuated along with the formation of fragments with molecule weight < 97.2 KD when extraction temperature increased. Amide I and II of GSSG were shifted to higher wavenumber while amide A and B to lower wavenumber in parallel with declined peak (7.3°) intensity by X-ray analysis as temperature increased. Gel strength, gelling temperature and melting temperature of GSSG (47–122 g, 9.30–12.18 °C and 16.87–21.34 °C) were lower than those of CBG (160 g, 22.01 °C and 28.70 °C) and TPSG (151 g, 13.90 °C and 21.34 °C) (p < 0.05). They decreased as temperature elevated in consistent with their gel microstructure with big size voids. These also coincided with their longer relaxation time showed by low field-nuclear magnetic resonance. GSSG50 (62.3 m2/g, 57.5 min) and GSSG55 (55.6 m2/g, 60.8 min) showed higher emulsion activity index and emulsion stability index (p < 0.05) as well as smaller size emulsion droplets than others. Results indicate that GSSG has poor gelling properties, but excellent emulsifying properties. They are greatly affected by extraction temperature. GSSG is proposed to be extracted at a temperature between 45 and 50 °C.
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