Supercritical CO2 extraction of Aurantiochytrium sp. biomass for the enhanced recovery of omega-3 fatty acids and phenolic compounds

authors	de Melo, MMR; Sapatinha, M; Pinheiro, J; Lemos, MFL; Bandarra, NM; Batista, I; Paulo, MC; Coutinho, J; Saraiva, JA; Portugal, I; Silva, CM
nationality	International
journal	JOURNAL OF CO2 UTILIZATION
author keywords	Aurantiochytrium sp.; Design of experiments; Docosahexaenoic acid; Microalgae; Supercritical fluid extraction
keywords	CARBON-DIOXIDE EXTRACTION; EUCALYPTUS-GLOBULUS BARK; FLUID EXTRACTION; DOCOSAHEXAENOIC ACID; OPTIMIZATION; MICROALGAE; CAROTENOIDS; OIL; METHODOLOGY; LYCOPENE
abstract	The microalgae Aurantiochytrium sp. is a strong alternative source of omega-3 fatty acids, including docosahexaenoic acid (DHA). This work encompasses the optimization of SFE conditions to maximize the total extraction yield eta(Total)), DHA content (C-DHA), total phenolics content (TPC), and antioxidant capacity (AOC) of the extracts produced from Aurantiochytrium sp. biomass. A full factorial experimental plan was performed, comprising three factors (pressure, temperature, and flow rate) and two levels (200 - 300 bar, 40 - 80 degrees C, and 6-12 g min(-1), respectively). The maximum and minimum experimental results were eta(Total) = 2.1 and 13.4 wt%, C-DHA= 27.3 and 39.3 wt. %, TPC = 1.19 and 2.24 mg(GAE )g(extract)(-)1 and AOC = 0.3 and 1.4 mg(TEAC )g(extract)(-1). Under the studied experimental conditions, increasing pressure up to 300 bar is the optimum to rise both eta(Total) and C-DHA. Temperature increase from 40 to 80 degrees C leads to opposing effects: it favors the concentration of phenolics in the supercritical extracts at the expenses of decreasing DHA content and total yield. Surface models were adjusted to eta(Total), C-DHA and TPC data, and the goodness of the fits ranged from coefficients of determination of 0.752-0.711 (TPC) to 0.997-0.994 (C-DHA). Under optimized conditions, supercritical extracts exhibited a DHA content more than 3.5-fold richer than fish oil, and 7.9-fold richer than the best alternative microalgae species (Pavlova lutheri) found in the literature.
publisher	ELSEVIER SCI LTD
issn	2212-9820
isbn	2212-9839
year published	2020
volume	38
beginning page	24
ending page	31
digital object identifier (doi)	10.1016/j.jcou.2020.01.014
web of science category	Chemistry, Multidisciplinary; Engineering, Chemical
subject category	Chemistry; Engineering
unique article identifier	WOS:000531069900004