Utilizing the pH-Shift Method for Isolation and Nutritional Characterization of Mantis Shrimp (Oratosquilla nepa) Protein: A Strategy for Developing Value-Added Ingredients

Abstract

This study focused on the production of protein isolates from mantis shrimp (MS). The pH-shift method was investigated to understand its impact on the protein yield, quality, and properties of the produced isolates. The first step was determining how the pH affected the protein solubility profile, zeta potential, and brown discoloration. The pH-shift process was then established based on the maximum and minimum protein solubilization. The solubilization pH had a significant impact on the mass yield and color of the produced protein, with a pH of 1.0 producing the maximum mass in the acidic region, whereas a maximum was found at a pH of 12.0 in the alkaline region (p < 0.05). Both approaches yielded mantis shrimp protein isolates (MPIs) with precipitation at a pH of 4.0 and a mass yield of around 25% (dw). The TCA-soluble peptide and TBARS levels were significantly lower in the MPI samples compared to MS raw material (p < 0.05). The MPIs maintained essential amino acid index (EAAI) values greater than 90%, indicating a high protein quality, and the pH-shift procedure had no negative impact on the protein quality, as indicated by comparable EAAI values between the mantis shrimp protein isolate extract acid (MPI-Ac), mantis shrimp protein isolate extract alkaline (MPI-Al), and MS raw material. Overall, the pH-shift approach effectively produced protein isolates with favorable quality and nutritional attributes.