Astaxanthin Recovery from Shrimp Residue by Solvent Ethanol Extraction Using Choline Chloride:Glycerol Deep Eutectic Solvent as Adjuvant

The present study investigated the use of choline chloride:glycerol deep eutectic solvent as an adjuvant for tuning the ethanol extraction of astaxanthin from Litopenaeus vannamei processing residues. The adjuvant concentration did not show a clear trend on the total carotenoid, however, the addition of adjuvant proved to be advantageous in the ultrasound-assisted experiments. In order to establish a balance between total carotenoid and productivity, an operational condition with ultrasound, 5% (m/v) choline chloride:glycerol and 10 min of incubation was selected, which provided 737.69 mu g g(-1) total carotenoids and 32.71 mu g g(-1) astaxanthin. When compared to the astaxanthin standard, the shrimp residue extract obtained greater antioxidant activity in free radical scavenging tests. In addition, the shrimp residue extract dramatically reduced the dosage of norfloxacin (up to 87.5%) and gentamicin (up to 75.0%) antibiotics in tests to inhibit the growth of Gram-negative bacteria.