Extraction and characterization of gelatin from chicken feet by acid and ultrasound assisted extraction

Abstract

The objective of this study was to extract gelatin from chicken feet using 2 different methods (acid extraction and ultrasound assisted extraction). The obtained gelatin was compared with commercial bovine gelatin in terms of gelatin powder and gelatin gel. Various properties such as, yield, pH, color (L*, a* and b*), proximate analysis (moisture, protein, fat and ash), Fourier Transform Infrared (FTIR) spectrum, maximum force and electrophoresis of gelatin were evaluated. The highest yield of chicken feet gelatin was obtained from acid extraction method with 4.05% (wet weight or 12.64% based on dry weight). Proximate analysis of chicken feet gelatin showed the acid extraction has the higher protein content than ultrasound assisted extraction with 90.06±1.43, while ultrasound assisted gelatin has the lowest moisture content with 5.40±2.44. However, there is no significantly different values of protein, fat, ash and moisture content between acid, ultrasound extraction and commercial bovine gelatin (p>0.05). pH of gelatin solution for both methods has range between 6.13-6.49. Amide A peak was shown at the wave numbers 3,322.12 cm-1 for gelatin extracted with acid condition and 3,619.04 cm-1 for commercial bovine gelatin.