Diet plays a significant role in human health and has been identified as a major
contributing factor to mortality associated with non-communicable diseases.
Numerous studies have demonstrated that unsaturated fats provide substantial
health benefits. Polyunsaturated fatty acids (PUFAs), which include omega-3 and
omega-6 fatty acids, are known to enhance cognitive and metabolic functions.
Microalgae, as abundant sources of bioactive compounds and essential nutrients,
are capable of producing a wide range of lipids, including glycolipids,
phospholipids (polar lipids), glycerolipids for neutral lipid storage, and free fatty
acids such as polyunsaturated fatty acids, as well as proteins and carbohydrates.
This study investigates the extraction and purification of omega-3 fatty acids from
the microalgae Chlorella vulgaris and Nannochloropsis oculata cultivated in the
Persian Gulf. Experimental design was carried out using Minitab software to
identify key parameters affecting extraction efficiency, including light intensity,
cultivation time, frequency, pressure, and other operational variables. Different
extraction techniques, namely ultrasonic-assisted extraction (UAE) and highpressure
homogenization (HPH), were employed individually as well as in an
integrated sequence (U→H). In addition, the urea complexation method was
applied for the purification of the extracted fatty acids.
The results indicated that the integrated U→H approach significantly enhanced
extraction efficiency. For Nannochloropsis oculata, an extraction yield of 96.65%
was achieved, while for Chlorella vulgaris, the yield reached 97.25%. During the
purification stage, the purity of polyunsaturated fatty acids increased from 38.80%
to 84.05% in Nannochloropsis oculata and from 29.65% to 82.00% in Chlorella
vulgaris. The concentration of eicosapentaenoic acid (EPA) reached 63.00% in
Nannochloropsis oculata and 5.40% in Chlorella vulgaris. Moreover, the α-
linolenic acid (ALA) content in Chlorella vulgari