Use of high and ultra-high pressure based-processes for the effective recovery of bioactive compounds from Nannochloropsis oceanica microalgae

Abstract

In this study, the recovery of different bioactive compounds from Nannochloropsis oceanica biomass is proposed using high and ultra-high pressure-based processes. The effect of different pretreatments to weaken cell wall was evaluated before pressurized liquid extraction (PLE). PLE was optimized using an experimental design with ethanol as extraction solvent. Optimum extraction conditions were found at 57 °C and 3 extraction cycles, providing a total carotenoids content of 115.1 ± 0.6 mg/g extract. Then, the residual biomass was extracted using limonene, and an enriched-lipid fraction was obtained. In parallel, ultra-high pressure extraction (UHPE) was applied directly to dry biomass to simultaneously disrupt the cell wall and extract the valuable compounds. Results showed that UHPE technique did not improve carotenoids extraction compared to PLE, although the recovery of polyunsaturated fatty acids was significantly better. Moreover, extracts were chemically characterized using high-performance liquid chromatography detection and gas chromatography coupled to mass spectrometry detection.