Shrimp residues generated by the seafood industrial processing are generally discarded in the environment without any further treatment, leading to a loss of nutritional value such as proteins, lipids, chitin, carotenoids, and minerals. This practice can lead to environmental problems due to the decomposition of these substances in the air. The objective of this study was to extract astaxanthin-rich materials from shrimp (Litopenaeus vannamei) industrial residue (WO) and smaller-scale residue meal (MO) in processing shrimp with soybean oil to evaluate their physicochemical characteristics, fatty acid content, and antioxidant potential. WO and MO were found to contain 27.48 and 33.34 µg g -1 of astaxanthin, respectively. The physicochemical properties of pigmented oils are established by legislation. The MO material showed significantly higher antioxidant activity compared to the soybean oil (control), especially when based on the oxygen radical absorbance capacity (ORAC) test, which showed antioxidant activity of 0.484 and 0.264 µmol eq Trolox g -1 for the MO and soybean oil (control), respectively, possibly accompanying their respective astaxanthin contents in the MO sample. The pigmented oils from both the shrimp residues showed significant potential for being used in the food industry due to their affordability and their high antioxidant activity.

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 µg g-1 total carotenoids and 32.71 µg 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.