AQUATIC SHRIMPS AS A RESOURCES OF BIOACTIVE MOLECULES

Abstract

To date, aquatic crayfish play a very important role both environmentally then economically. Depending on the species they can be invasive, bioindicators or used in human nutrition. Among these species today appear to be important one marine and one of freshwater species: respectively Aristaeomorpha foliacea and Procambarus clarkii. The first is an economically important species highly appreciated by consumers, while the second is an invasive species responsible of the disappearance of the autochthonous species and of serious impacts on aquatic ecosystems (SOUTY-GROSSET et al., 2016). In the case of A. foliacea, the production of waste to date is considerable due to the large quantity of exoskeletons that are which constitute both environmental and economic damage for disposal companies. In the case of P. clarkii being that it is a very dangerous species for freshwater ecosystems, to date it is very important carrying out eradication or control of its distribution. Using the exoskeleton of these species is possible to obtain bioactive molecules such as chitosan. All these aspects are part of the purpose of our study which is part of two project: the PO FEAMP 2014-2020 project entitled "Census, characterization, control and valorization of the Louisiana red shrimp (Procambarus clarkii) in Sicily" and Interreg Italia-Malta entitled "Bythos Extend". In particular, the preparations of the flours and the extractions of chitosan and astaxanthin from the exoskeletons have already been developed in the Bythos I project (MAURO et al., 2022). These protocols were used to extract chitosan and astaxanthin from P. clarkii exoskeletons of different Sicilian lakes: the Rosamarina Lake and the Gorghi Tondi Lake. The obtained chitosans were analyzed using a Jasco FT/IR 420 spectrometer. On flours, were evaluated total phenolic content (Folin-Ciocalteu reaction), ferric ion reducing antioxidant power (FRAP) and radical scavenging activity assays (ABTS and DPPH). The reducing power and radical scavenger activity of flour of A. foliacea was significantly higher than P. clarkii. Flours of the two species of P. clarkii, as expected, showed comparable reducing power. ABTS, DPPH and FRAP radical scavenger activity assays were conducted on astaxanthin and chitosan showing no significant differences. These results are important to evaluate a possible use of these bioactive products in cosmetic, nutraceutical, and/or medical application.