Processing optimization and functional properties of gelatin from shark (Isurus oxyrinchus) cartilage

Gelatin processing from shark (Isurus oxyrinchus) cartilage was optimized by response surface methodology: the dependent variable was gelatin yield and independent variables were sodium hydroxide concentration and treatment time for the alkali treatment, and extraction temperature and time for the hot-water extraction. Predicted maximum yields of 79.9% for gelatin processing were obtained under the conditions of alkali treatment with 1.6N sodium hydroxide for 3.16 days and hot-water extraction at 65 °C for 3.4 h. Amino acid composition and functional properties of shark cartilage gelatin were examined in comparison to two porcine skin gelatins. Shark cartilage gelatin had lower concentration of hydroxyproline than the two porcine skin gelatins. Shark cartilage gelatin showed worse turbidity than the two porcine skin gelatins. Foam formation ability, foam stability, water-holding capacity and gel strength of shark cartilage gelatin were lower than the two porcine gelatins, but fat-binding capacity was higher in the shark cartilage gelatin.