Multistage Countercurrent Extraction of Abalone Viscera Oil and Its Hypolipidemic Action on High-Fat Diet-Induced Hyperlipidemia Mice

Background/Objectives: Marine-derived oils rich in long-chain polyunsaturated fats have long been associated with positive effects on plasma lipid levels and anti-inflammatory responses. Abalone viscera are rich in oils that are rarely extracted and made available. Methods: Abalone viscera oil (AVO) was extracted by multistage countercurrent extraction using ethanol as a solvent, and its oil quality, fatty acid composition, and in vitro antioxidant activity were determined. Meanwhile, the anti-hyperlipidemic effect of AVO on HFD-induced hyperlipidemia mice was evaluated. Results: The abalone viscera were extracted at a solid–liquid ratio of 1:3 with an oscillation frequency of 300 rpm for 40 min, and the extraction rate was 81.18% after four-stage countercurrent extraction. The acid value, iodine value, peroxide value, vitamin E, and astaxanthin of AVO were 1.26 mg KOH/g, 140.9 g/100 g, 3.6 meq/kg, 105 mg/kg, and 533.8 mg/kg, respectively. The unsaturated fatty acids of AVO account for 56.60%, with eicosapentaenoic acid (C20:5n3) and arachidonic acid (C20:4n6) the two predominant PUFAs, and oleic acid (C18:1n9) the most dominant MUFA. The DPPH, ABTS, and ·OH radicals scavenging capacities of AVO increased with concentration, and the IC50 values were 6.30 mg/mL, 0.45 mg/mL, and 8.95 mg/mL, respectively. Moreover, the administration of AVO significantly alleviated HFD-induced weight gain, liver fat accumulation, lipid disorder, and oxidative stress in mice. Conclusions: Collectively, our study provides a theoretical basis for the application of AVO and the comprehensive utilization of abalone viscera, which helps increase the additional value of abalone.