Study on electrostatic separation technology and characterization of shrimp shell protein

Abstract

Shrimp shell protein is a high-quality protein with wide-ranging applications in feed, pharmaceuticals, and food industries. However, current methods for its production often involve the use of harsh chemicals, resulting in the generation of polluting effluents, making green alternatives highly desirable. This study combined demineralization of shrimp shell (Fenneropenaeus chinensis, Osbeck, 1765) with ultrafine grinding and electrostatic separation techniques to extract and separate the protein. The research findings revealed that shrimp shell contain 40.64 ± 0.52 % protein, which increased to 52.61 ± 1.12 % after demineralization treatment. Impact grinding, compared with cutting grinding, facilitated the production of demineralized shrimp shell ultrafine powder with more uniform distribution and smaller particle size. However, only demineralized shrimp shell powder obtained through cutting grinding achieved an increase in protein purity from 61.82 ± 0.75 % to 72.72 ± 0.83 % after electrostatic separation. The electrical properties of shrimp shell protein and chitin suggest that shrimp shell protein is more conductive than chitin, while shrimp shell chitin is more insulating and less prone to charge exchange with the counter material in a direct current electric field. The total amino acid content of shrimp shell protein obtained through electrostatic separation (715.831 mg/g protein) was higher than that obtained through traditional wet extraction (533.455 mg/g protein). Additionally, the amino acid score (AAS) of shrimp shell protein obtained via electrostatic separation was higher compared to that obtained via wet extraction. The wet extraction process significantly influenced the nutritional and structural properties of shrimp shell protein. This study confirms the potential application of electrostatic separation technology in the extraction of animal-derived shrimp shell protein.