Amino acid-based natural deep eutectic solvent combined with ultrasonic extraction: green extraction of astaxanthin from shrimp shells

The continuous accumulation of shrimp shell waste in daily life is not only a source of environmental pollution but also a waste of resources. The conversion of shrimp shell waste into valuable bioactive components using cost-effective and environmentally friendly methods is still of research interest. Based on the above intention, in this study, a green and efficient ultrasound-assisted natural deep eutectic solvent (NADES) method was developed to recover astaxanthin (AST) from shrimp shells. AST was extracted using selected six different types of NADESs and organic solvent (acetone), and the extraction conditions were optimized. Under the optimal extraction conditions, NADES synthesized by lysine-citric acid showed an extraction efficiency of 112.80 μg/g for AST, which was more than 5 times higher than that extracted with acetone. Furthermore, the hydroxyl radical scavenging tests revealed that the AST recovered with lysine-citric acid had higher antioxidant capacity than the AST extracted with acetone. This NADES combined with ultrasound extraction method provides economic and environmental benefits by extracting bioactive substances from shrimp shell waste. Graphical Abstract