A comparison of harvesting and drying methodologies on fatty acids composition of the green microalga Scenedesmus obliquus

• Published in: Biomass & bioenergy 2020-01, Vol.132, p.105437, Article 105437
• Main Authors: Oliveira, Carlos Yure Barbosa de, Viegas, Thayna Lye, Lopes, Rafael Garcia, Cella, Herculano, Menezes, Rafael Silva, Soares, Aline Terra, Antoniosi Filho, Nelson Roberto, Derner, Roberto Bianchini
• Format: Article
• Language: English
• Subjects: Biodiesel; Biomass drying; Biomass recovery; Flocculation; Saturated fatty acids
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2019.105437

Harvesting and drying processes are still obstacles in the microalgae production chain. In this study, a combination of different harvesting and drying methods for Scenedesmus obliquus was proposed. S. obliquus was cultivated in a pond raceway for 15 days until reaching stationary phase. The culture was separated by different harvesting methods (centrifugation and flocculation) and drying methods (freezing, freeze-drying and oven drying), each combination in triplicate. Flocculation did not influence FAME yield of S. obliquus, except when the biomass was dried in an oven. The biomass that was only frozen had the lowest FAME content due to the presence of reactive water in the biomass. In contrast, frozen biomass had higher content of saturated and monosaturated fatty acids; freeze-drying or oven drying caused an enrichment of the polyunsaturated fatty acids content. In conclusion, if the biomass will be used to extract polyunsaturated fatty acids, freeze-drying would be more appropriate. On the other hand, if the purpose of the biomass is to produce biodiesel, the best process would be to just freeze the biomass. •Harvesting and drying methods of the green microalga Scenedesmus obliquus biomass were tested.•Harvesting methodologies did not affect the fatty acid profile of Scenedesmus obliquus.•In contrast, the fatty acid content did change when they were dried using different methodologies.•If the biomass will be used to extract polyunsaturated fatty acids, freeze-drying would be more appropriate.•On the other hand, if the purpose is to produce biodiesel, the best process would just be to freeze the biomass.