Valorisation of Algerian Aquaculture By-products of Mytilus galloprovincialis through Protein Extraction: Nutritional Composition, Biological Properties and Toxicological Profile

Abstract

This study evaluated the nutritional composition, biological activities and sanitary safety of a protein concentrate (PC) obtained from processing by-products of Mytilus galloprovincialis collected along the Algerian Mediterranean coast. The extraction protocol combined a delipidation step with alkaline solubilisation to maximise protein recovery. The resulting PC exhibited high crude protein content (80.41% dry matter, DM), low lipid content (3.16% DM), and a balanced amino acid profile enriched in glutamic acid, glycine and taurine. Mineral analysis revealed appreciable concentrations of calcium, phosphorus, potassium, selenium and zinc, alongside detectable levels of vitamins C, E and B12. Antioxidant activity was confirmed through DPPH, FRAP, H₂O₂ scavenging, TBARS inhibition and phosphomolybdenum reduction assays. The PC also demonstrated significant anti-inflammatory and antihemolytic activities in vitro, suggesting a multifunctional bioactive potential. Concentrations of toxic trace metals remained below the limits established by EU Regulation 2023/915, and microbiological analyses confirmed satisfactory hygienic quality. Overall, the findings support the valorisation of mussel-processing by-products as a sustainable, high-value protein source for food and nutraceutical applications, within a circular marine bioeconomy framework.