Microwave-Assisted Brine Extraction for Enhancement of the Quantity and Quality of Lipid Production from Microalgae Nannochloropsis sp.

Abstract

Toward attaining a sustainability and eco-friendly process, a green and low-cost solvent—brine (NaCl solution) is proposed, as microwave-assisted extraction (MAE) technique solvent to extract lipids from microalgae Nannochloropsis sp. The effect of NaCl concentration on the quantity and quality of the extracted lipid was assessed, while MAE parameters were optimized using response surface methodology (RSM). The content of fatty acid methyl esters (FAMEs) in the lipid was analyzed by using a gas chromatography—flame ionization detector (GC/FID). The highest lipid yield (16.1%) was obtained using 10% (w/v) brine at optimum extraction parameters of 5% (w/v) solid loading, 100 °C, and 30 min. The lipid extraction yield via optimized MAE-brine technique was thrice better than that Soxhlet extraction did and only 2% less than Bligh and Dyer (B&D) lipid extraction, which utilized harmful solvents. The proposed MAE-brine technique offered better quality lipids containing the highest amount of polyunsaturated fatty acids (PUFA) (44.5%) and omega-3 fatty acids (FAs) (43%). Hence, the MAE-brine solvent technique appears to be a promising extraction method for cheaper, greener, and faster extraction of a high-quality lipid for specialty food applications.

Kinetics Study of Microwave-Assisted Brine Extraction of Lipid from the Microalgae Nannochloropsis sp.

“…The highest extraction temperature and longest extraction time of 100 • C and 30 min resulted in the highest lipid yield of 16.1%. According to previous work [6], this yield was three-fold better than that of Soxhlet extraction and only 2% less than achieved with the Bligh and Dyer (B&D) lipid extraction method, which utilizes harmful solvents. Table 1.…”

“…The microwave extraction was performed in a 250 mL round bottom borosilicate flask. For the kinetic experiments, the optimised conditions from a previous work [6] were used with salt concentration of 10% (w/v) and solids loading of 5% (w/v). The runs were set for a maximum time of 30 min.…”

“…The kinetic experiments were conducted for 30 min using MAE-brine solvent under the previously obtained optimum extraction conditions [6]. Lipid extraction were done using 10% (w/v) NaCl as solvent and 5% (w/v) solid loading at extraction temperatures of 60, 70, 80, 90 and 100 • C. Table 1 lists the experimental results for the lipid extraction.…”

“…The microwave-assisted extraction (MAE) technique has enormous potential as a promising method for microalgal lipid extraction, as it is non-intricate and eco-friendly [3], and useful for lipid extraction due to the high heating rate [3], minimal amount of solvent usage [4], lower operating cost and fast extraction time [5]. Moreover, utilizing a green and cheaper solvent such as brine can contribute to further reduction of the extraction cost, food safety and environmental pollution [6].…”

Study Literature of Extraction Lipid Method from Microalgae Nannochloropsis sp

“…Finding the most efficient method and optimized conditions for the extraction of lipids were important for reducing the cost of biodiesel production from microalgae [10]. Based on literature studies, it was found the advantages and disadvantages of several existing extraction methods [12,13]. According to research that has been done by M. H. Kwon et al [13] in Table 2, BDM was mostly a solvent extraction process, which is influenced by factors such as the type of organic solvent, temperature, and cell wall rigidity.…”