A novel extraction approach and unique physicochemical properties of gelatin from the swim bladder of sturgeon

BACKGROUND Gelatin is traditionally produced from mammals and widely applied in the food industry. The production is tedious, time-consuming and environment-unfriendly, while the application is restricted because of zoonosis risk and religious sentiment. RESULTS Gelatin was extracted by hot water from sturgeon swim bladder after defatting with alcohol and hexane. The yield reached to 94.15% under the optimized conditions of 50 degrees C, 30 min and 10 mL g(-1). Its amino acid and subunit profiles were similar to type I collagen. Compared to commercial porcine, bovine and piscine gelatins, it exhibited higher whiteness (3.38), emulsion activity (171.76 m(2) g(-1)), gel strength (853.23 g), water-holding capacity (92.37%) and viscoelasticity (0.03). But the transmittance (40.56% at 450 nm and 59.07% at 620 nm), emulsion stability (30.09 min), foam expansion (203.00) and stability (26.92), gelling (16.88 degrees C) and melting temperature (21.80 degrees C) were lower. While the pH (6.87) and viscosity (28.60 mPa s) were moderate. Moreover, it made better hydrogels and nanofibers. CONCLUSION Gelatin was extracted from sturgeon swim bladder using a clean and efficient approach, and exhibited unique properties and great potential for the food industry.

Automated summary

In this study, gelatin was extracted from sturgeon swim bladder using a clean and efficient method, showing unique properties with great potential for the food industry. Compared to commercial porcine, bovine and piscine gelatins, sturgeon gelatin exhibited higher whiteness, emulsion activity, gel strength, water-holding capacity, and viscoelasticity, but lower transmittance, emulsion stability, foam expansion and stability, gelling, and melting temperatures. Additionally, sturgeon gelatin showed moderate pH and viscosity and was capable of producing better hydrogels and nanofibers.