Enhanced oil yield from Indian mackerel (Rastrelliger kanagurta) via Soxhlet extraction method: A response surface methodology (RSM) based approach

Abstract

The production of fish oil, especially from species like Indian Mackerel (Rastrelliger kanagurta), is important both economically and nutritionally because of its high omega-3 fatty acid content. This study aimed to improve the oil yield from Indian Mackerel by using the Soxhlet extraction method and petroleum ether as a solvent. The extraction temperature, time, and solvent-tosample ratio all affect oil yield. Thirteen (13) experimental runs were conducted to evaluate the effects of different extraction parameters on oil yield. These trials varied the solvent-to-sample ratio (20–40 ml/g), extraction temperature (50–70 ◦C), and extraction time (3–6 hours). The fish samples were oven-dried and ground into a uniform particle size of 0.5 mm. After extraction, the solvent was evaporated with a rotary evaporator, and the oil yield was determined. ANOVA results showed that oil yield was significantly influenced by extraction time and temperature (p < 0.0001), with the greatest yield of 33.12% found at 70 ◦C, a 6-hour extraction period, and a solvent-to-sample ratio of 30 ml/g. The effect of the solvent-to-sample ratio was determined to be insignificant. The extraction procedure was optimised using the Response Surface Methodology (RSM) and Design Expert software (version 8.0.7.1). The optimum parameters for providing the greatest oil production were identified: 72 ◦C, 6.5 hours of extraction time, and a solvent-to-sample ratio of 30.42 ml/g, yielding 35.60%.