Amino acid Composition of Gelatin Extracted from the Scales of Different Marine Fish Species in Kenya

Abstract

Gelatin in this study was extracted by an enzymatic process from the scales of three marine fish species; Lutjanus sebea (Red snapper), Lethrinus harak (Black spot emperor) and Scalus ghobban (Blue barred parrot fish). Concentration of bacteria for mass production of enzyme was done in a fermentation medium using a bio reactor. Scales were hydrolyzed at 500C and the pH maintained at 12. Complete hydrolysis took between 20 and 23 days for all species. The yield for the dried gelatin was between 28.2% and 41.4% for the marine fish scales under study. Fourier transform infrared spectra showed the presence of amide bands and two other additional absorption bands, indicating the presence of amide bonds for all the three species. The amino acid composition analysis for the gelatin of three species was then done showing the presence of 16 amino acids. Glycine was the most abundant for all the three species with about 35% followed by Alanine both adding up to around 50% of the total amino acid compositions. The amount of Proline was high for red snapper at over 14.2% compared to 11.1% and 11.6% for blue barred parrot fish and black spot emperor respectively.