Effect of different polarity solvents on ALG (Nannocloropsis sp.) oil extraction

In this study it is aimed to investigate Omega-3 fatty acids rich algal oil production methods from microalga Nannochloropsis sp. The Nannochloropsis sp. algae were growth in f/2 medium with using photoreactor. Harvested microalgae biomass was dried in freeze dryer in order to remove its moisture. Dried algae biomass was milled and standardized with using sieve. Response surface methodology was used for omega-3 rich algal oil extraction from algal biomass in order to obtain optimum oil extraction conditions. The extraction parameters which significantly affect to oil yield was extraction temperature and extraction time whereas the solvent:alga ration was insignificant factor affecting oil yield. Optimum conditions for extraction of omega-3 rich algal oil from algal biomass were as follow: extraction temperature, 44.30 ºC; extraction time, 62.46 min.; solvent:alga ration, 19.9:1. The oil yield and omega-3 content obtained under the these optimum conditions were % 69.31 and %32.03, respectively. Extraction with different polarity solvents resulted in the highest oil yield, the extreme result of methanol with the highest polarity solvent. When the fatty acid profile was examined, it was found that the algal oils obtained were statistically significant (P <0.05) in the contents of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Polyunsaturated fatty acids (PUFAs), the group that includes omega-3 fatty acids, were detected the highest in the methanol-treated sample (20,57 %). The samples prepared with chloroform were identified as the samples with the lowest PUFA content (11,30).