Effect of Extraction Parameters on the Properties of Gelatin from King Weakfish (Macrodon ancylodon) Bones

Abstract

Fish bones are important sources of collagen and are usually discarded by the processing industries. A response surface methodology was utilized to optimize the extraction process of gelatin from king weakfish (Macrodon ancylodon) bones submitted to alkali pre-treatment. The experimental responses were gel strength and gelatin yield, while the studied variables were sodium hydroxide concentration (2 and 4 g/100 g), maceration time (48 and 72 h) and extraction temperature (60 °C and 80 °C). An increase in extraction temperature carried out a significant (p ≤ 0.05) reduction in gelatin gel strength. The increase in the NaOH concentration during maceration increased the process yield. Extraction temperature, NaOH concentration and their interaction had a pronounced effect on process yield. High extraction temperatures resulted in higher yields, but reduced the strength of gelatin gel.