Ultrasound-Assisted Extraction Improved the Extraction Rate, Omega-3, and Polyunsaturated Fatty Acid Content of Fish Oil From Atlantic Bonito Waste

This study presents an innovative approach for extracting fish oil from Atlantic bonito (Sarda sarda) waste, optimizing the extraction yield and omega-3, polyunsaturated (PUFA), and saturated fatty acid (SFA) content. The response surface method was used to investigate vital parameters such as temperature, time, and solvent-to-solid ratio. The optimal extraction conditions were a 16 mL/g hexane-to-solid ratio, 60 degrees C temperature, and 80 min extraction time for the highest extraction yield, omega-3, and PUFA with a desirability of 0.93. These adjusted settings resulted in a 45.11% (g/g freeze-dried fish waste) oil extraction yield, 39.41% (g/g extracted fish oil) omega-3 fatty acid, and 45.21% (g/g extracted fish oil) PUFA content. Compared to the standard Soxhlet extraction procedure, ultrasound-assisted extraction (UAE) had a 90.50% efficiency at extracting fish oil and resulted in improved omega-3 and PUFA content and decreased SFA content (p < 0.05). Additionally, the oil obtained using UAE had improved oxidative stability when compared to the Soxhlet oil in terms of induction time, acidity, peroxide, p-anisidine, and total oxidation (TOTOX) values. The implications of these findings extend to various industries, including food, pharmaceuticals, and nutraceuticals, where enriched omega-3 and PUFA content could prove beneficial. These findings provide important insights into optimizing ultrasound-assisted procedures, opening the way for further improvements in fish oil extraction and its numerous applications. Practical Applications: Ultrasound-assisted extraction (UAE) for obtaining fish oil from discarded Atlantic bonito has practical implications in various sectors. The UAE achieved a success rate of 90.50% in extracting fish oil, surpassing traditional methods, and showcasing its superior efficiency. The extracted oil has high omega-3 and polyunsaturated fatty acids (PUFAs) content while minimizing the saturated fatty acids contents, making it highly beneficial for the food, pharmaceutical, and nutraceutical industries. The higher oxidative stability of UAE compared to Soxhlet extraction makes it a preferable option for enhancing oil quality. The eco-friendly attributes of this product, which involve the use of less solvent and shorter extraction durations, are in line with sustainability goals in the fields of fisheries and waste reduction. Essentially, UAE is an efficient technique with wide-ranging applications in improving the quality of fish oil and promoting sustainability objectives.