Exploring the Biotechnological Value of Marine Invertebrates: A Closer Look at the Biochemical and Antioxidant Properties of Sabella spallanzanii and Microcosmus squamiger

SIMPLE SUMMARY: Marine invertebrates are a rich source of natural products with multiple commercial applications. However, little is known about the biotechnological potential of Sabella spallanzanii and Microcosmus squamiger. Aimed at filling this gap, this work evaluated such species for biochemical, antioxidant and metal chelating properties. Both species had interesting nutritional profiles in terms of crude protein and fat, among others. Regarding amino acids, S. spallanzanii and M. squamiger were found to be rich in arginine and taurine, respectively, while the most abundant minerals were sodium, calcium, and potassium, in both species. Methanol extracts of both species had antioxidant and metal chelating capacity. Fucoxanthinol and fucoxanthin were the major carotenoids in the M. squamiger dichloromethane extract. The fatty acid (FA) profile was strongly influenced by the type of extract. Saturated FA were higher than unsaturated ones in methanol extracts, while unsaturated FA prevailed in the dichloromethane extracts. Low n-6/n-3 ratios were obtained. Our results suggest both species as sustainable sources of bioactive products with several applications, for example, as food ingredients, as fish feed, and as ingredients for veterinary products. ABSTRACT: Sabella spallanzanii and Microcosmus squamiger were profiled for proximate composition, minerals, amino acids, fatty acids (FA), carotenoids, radical scavenging activity on the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC) and iron and copper chelating properties. Microcosmus squamiger had the highest level of moisture and crude protein, S. spallanzanii was enriched in crude fat and ash. Both species had similar levels of carbohydrates and energy. There was a prevalence of arginine and glycine in S. spallanzanii, and of taurine in M. squamiger. The most abundant minerals in both species were Na, Ca, and K. The methanol extract of S. spallanzanii had metal chelating properties towards copper and iron, while the methanol extract of M. squamiger was able to chelate copper. M. squamiger extracts had similar ORAC values. Fucoxanthinol and fucoxanthin were the major carotenoids in the M. squamiger dichloromethane extract. Saturated FA were more abundant than unsaturated ones in methanol extracts, and unsaturated FA prevailed in the dichloromethane extracts. Palmitic acid was the predominant FA in methanol extracts, whereas eicosapentaenoic (EPA) and dihomo-γ-linolenic acids were the major compounds in dichloromethane extracts. Low n-6/n-3 ratios were obtained. Our results suggests that both species could be explored as sources of bioactive ingredients with multiple applications.