Anais do Simpósio Latino Americano de Ciências de Alimentos
Anais do 14 SLACA - Simpósio Latino Americano de Ciência de Alimentos

Proteins are part of the human diet and their nutritional function is to maintain good mental and physical health. However, this nutritional quality depends largely on its composition in essential amino acids, digestibility and bioavailability. Fish protein powder, extracted from either underutilized species or byproducts of the fish industry, is one of alternative. The aim of this study was to evaluation nutritional and functional properties proteins recovered from the muscle of Nile tilapia (Oreochromis niloticus) using pH shift processing and to evaluate the bioavailability of essential amino acids. The proximate composition, functional properties, essential amino acid composition, in vitro digestibility, apparent bioavailability, chemical score of amino acids and SDS-PAGE were determined for Nile tilapia protein isolate obtained by process the acidic protein isolate (API) and basic protein isolate (BPI). High values protein observed both by API (95.13 ± 0.17) and by the BPI (93.57 ± 0.31), in dry basis. The highest solubility was obtained in pH 11 (98.19%), the maximum water holding capacity was presented at pH 11 (27.83 mL H2O/g protein), the oil holding capacity were 3.64 and 3.51 mL/g protein for API and BPI respectively. The digestibility was high, being for API 92.59 ± 1.07 and BPI 90.33 ± 0.48. The amino acids that presented a higher concentration were lysine and leucine for both acid and alkaline treatments, histidine was the limiting amino acid with a score of 1.23 and 1.14 mg/g for API and BPI respectively. The electrophoresis gel shows a similar pattern for API and BPI treatments showing actin band (50 KDa) in both treatments with strong intensity. The results show that the isolated protein exhibited a high content of essential amino acids and digestibility, indicating that the protein has a high nutritional quality.