Functional Properties of White Shrimp (Litopenaeus vannamei) By-Products Protein Recovered by Isoelectric Solubilization/Precipitation

The processing of fish in general entails quantities of by-products, such as exoskeleton and cephalothorax of shrimp, which may reach 70%. Protein recovered from by-products has been investigated in recent years for its ability to offer more nutritious foods and improved functional properties. The objective of the present study was the use of the pH shifting process to recover proteins from solubilization and precipitation that are present in the by-products (heads and shells) of white shrimp (Litopenaeus vannamei). The proximal composition of the by-products presented 58.5% protein (d.b). The isoelectric point used to precipitate the protein was defined at pH 4. The protein concentrate presented 73.1% of protein. The yield of the protein concentrate mass resulted in 47.8% (w.b). The greatest solubility found for the protein concentrate was 51.3% at pH 8. The oil and water retention capacity resulted in values of 8.5 and 2.5 mL/g of protein, respectively, and the highest emulsifying capacity was found at pH 8. The by-products and concentrate amino acids profiles confirmed the presence of 16 amino acids. In general, the shrimp protein concentrate obtained showed the potential to be included as an ingredient in food formulations.