Abstract

An Research on protein hydrolysate has been performed by using various types of fish and enzymes, but there is limited research on the nutritive value of visceral waste proteins of tilapia. The present study aimed to determine amino acid profile and composition (water, protein, fat and ash content) of protein hydrolysates prepared from viscera of Nile tilapia (Oreochromis niloticus). Alcalase enzyme was used as the hydrolytic enzyme at a concentration of 1.5 % (w/v), pH 7.9, and temperature of 55.80 °C for 1.5 h. Fresh Nile tilapia viscera had a high protein content of 35.14% ± 0.02 (dry basis) and the defatting process reduced fat content from 60.24 ± 0.04 to 57.81% ± 0.01 (dry basis). The results indicated that the hydrolysis of Nile tilapia viscera led to an increase in the protein content (62.81% ± 0.18) (dry basis). Furthermore, hydrolysis process also decreased the moisture content (11.56 % ± 0.49), fat content (16% ± 0.14), and ash content (5% ± 0.17) (dry basis). Glutamine had the highest amino acid level in hydrolysates (3.85 g/100g), whereas cysteine the lowest level (0.32 g/100g). In conclusion, Nile tilapia protein hydrolysates contain sufficient quantities of the essential amino acids that can be used as a source for fish feed protein. Moreover, chemical characteristics and amino acid profile of Nile tilapia protein hydrolysates indicated a high nutritional value which could be met adult human nutritional needs.