Yield of gelatin from catla, rohu, grass carp and mixed scales and their amino acid composition

Abstract

Gelatin is mostly used as food ingredients. Its applications in food industries varies from enhancer as elasticity, consistency and stability of food products. Gelatin is also used as a stabilizer, particularly in dairy products. In pharmaceutical industry, the manufacture of pharmaceutical capsules, ointments, cosmetics, tablet coatings and emulsions often involve gelatin as one of the important ingredients. Gelatin also finds application in photography and some specialized industries. Gelatin is obtained from collagenous raw materials mostly from skin and bones of bovines and skin of porcines those are not “Halal”. Therefore, there is a need to extract gelatin from ‘Halal’ sources like fish scales and skins which may be collected from fish market and fish processing industries. This study extracted gelatin from the scales of catla, rohu, grass carp and mixed type. Thereafter, amino acid profiling of the gelatin extracted from the scales of catla and rohu was done. Grass carp (0.78 ± 0.03) and mixed types of scales (0.78 ± 0.02) yielded similar level of gelatin percent. However, rohu had the lowest recovery of percent gelatin (0.61 ± 0.05). Scales of catla had 0.72 ± 0.06% gelatin. Of the total 14 amino acids, highest percent of Glutamic acid (6.58 %) was found in the gelatin extracted from the scales of catla with lowest percent of Leucine (0.76 %). The percent Methionine and Lysine found were 0.79 and 4.36%, respectively. Arginine was also present at 1.36% in the gelatin extracted from the scales of catla. Gelatin extracted from rohu had highest percent of Glutamic acid (6.14 %) with lowest percent of Leucine (0.59 %). The percent Methionine and Lysine found were 0.85 and 4.15%, respectively. Arginine was also present at 1.33% in the gelatin extracted from the scales of rohu. Of the 10 EAAs, 8 were found in the two of gelatin extracted from the scales of catla and rohu. Among them highest percent Lysine (4.36%) was found in the gelatin extracted from the scales of catla. While the highest percent of Lysine (4.15 %) was found in the gelatin extracted from the scales of rohu, the lowest percent (0.59%) was Leucine. Quantification of fish scales from the fish markets of Bangladesh and extraction optimization may enhance both yield and efficiency.