Produção e caracterização de hidrolisado protéico provenientes de resíduos de tilápia ( Oreochromis niloticus)

Abstract

With the intensification of fish farming in Brazil the cultivation of tilapia has been expressive, mainly in the Northeast and Southeast. Due to the growth of exports, it had pushed up the installation of processing units fillet because of their high commercial value can yield more than 30% of the weight of the animal. The rest is considered waste of no commercial value (meat remains, head, skin, bones, scales and viscera) which had to be discarded without treatment, represent a serious environmental problem. However, carcasse is a rich material protein while, visceras is a source in digestive enzymes, including proteases, which can be used in the food industry and the production of protein hydrolysates. Thus, the objective of this study was to produce and characterize fish protein hydrolysate by enzymatic autolysis, and compare its performance with a commercial enzyme. For this, the following enzymatic sources were used: crude extracts of intestine with concentrations of 100 and 600 mg / mL and an extract with commercial alcalase to 0,5% (v/v). All extracts had their proteolytic activities and protein concentration determined. Later, three fish protein hydrolysates were produced (n = 3), by two autolysis (FPH100 and 600) and another enzyme with alcalase (HPPcom). The degree of hydrolysis (DH) was calculated as the soluble peptides concentration after TCA precipitation. In the end of 4 hours the GH of FPH600 was 61, 82% of HPPcom was 44,66% and FPH100 was 28,40%. An aliquot of the last time of hydrolysis of each hydrolysate was applied in SDS-PAGE and the molecular weights were estimated to be 116,25 and 37,41 kDa. Enzymatc activities were demonstrated by zymogram. The centesimal composition showed that the carcass of tilapia has 423.60 g/kg crude protein and FPHcom, 100, and 600 have 584,80; 407,00 and 508,20 g/kg, respectively. The amino acid composition, as well as the profile of essential fatty acids, showed to supplyt the nutritional requirements of carnivorous and omnivorous shrimp in the juvenile phase. These data showed that the proteases acted on the hydrolysis and FPH produced by autolysis have characteristics to be used in the production of feed for aquatic organisms.