Effect of various pretreatment methods prior to extraction of omega 3 fatty acids from Nannochloropsis gaditana

Abstract

Microalgae constitute a source of bioactive compounds offering a variety of nutraceutical and pharmaceutical applications. Amongst them, the omega-3 long-chain polyunsaturated fatty acids, such as eicosapentaenoic (EPA, 20:5 n-3), and docosahexaenoic (DHA, 22:6 n-3) acids are known for their beneficial effects on human health. There is currently a large demand for microalgae in the nutraceutical and pharmaceutical industry due to their health-promoting effects. High scale economically feasible microalgae based oil depends on optimizing the entire production process. To make it more economically attractive, a feasible cell disruption method should be established to ensure a low operating cost, high product recovery, and high quality of the recovered lipids. The aim of this study was to compare different pretreatment methods that enhance the lipid yield from the extraction process. In the present study, it was found that ultrasonic assisted extraction produces the highest lipid yield of 12 g followed by enzymatic treatment with 8.8 g per 100 g of dry wt. EPA yield also found to be high in ultrasonic disruption showing 32.5 mg/g, while, the lowest yield quantified in control and acid treatment with 18.2 mg and 18.9 mg/g respectively. Through further investigations, it was justified that pretreatment methods have the potential to reduce energy cost required for the conventional functional lipid extraction.