pH-Solubilzation Process as an Alternative to Enzymatic Hydrolysis Applied to Shrimp Waste

Waste materials derived from shrimp processing signify 40 to 45 % of the weight of the catch or harvest. For Biotechnology, waste materials are secondary material, as contrast of raw materials, to generate value-added products, such as chitin, protein, and pigments. We used the pH-shift and enzymatic autohydrolysis processes to obtain protein concentrates from the cephalothorax of whiteleg shrimp (Penaeus vannamei). Protein recovery by auto-hydrolysis and pH-shift was 83.3 % (sum of two fractions) and 87.5 respectively. Functional properties from protein concentrates were assayed. The protein concentrates obtained were: precipitated protein at pH=4.0 (PP4), remaining soluble protein at pH=4.0 (SP4), and hydrolyzed protein (3HP). Precipitated protein (PP4) had 50 % foam stability; soluble protein (SP4) 31.5 %, and hydrolyzed protein had no foam stability. Emulsion capacity of the protein concentrates was not different from egg albumin (control protein). Hydrolyzed protein had higher emulsion stability than the other protein concentrates. Protein concentrates from the pH-shift process had good balance of amino acids. Histidine and valine was not detected in hydrolyzed protein. The pH-shift process demonstrated to be an alternative for protein hydrolysis to recover protein from shrimp cephalothorax.