Time filter

Source Type

Gilbert-Lopez B.,Institute of Food Science Research CIAL UAM CSIC | Mendiola J.A.,Institute of Food Science Research CIAL UAM CSIC | van den Broek L.A.M.,Wageningen UR Food & Biobased Research | Houweling-Tan B.,Wageningen UR Food & Biobased Research | And 4 more authors.
Algal Research | Year: 2017

The fractionation of algae biomass in several high-value compounds that can be used as ingredients in other applications sets the basis of the algae biorefinery approach. The present study aimed at the extraction and fractionation of bioactive compounds from the microalga Scenedesmus obliquus, by means of applying a sequential process without the manipulation of the biomass in the extraction cell. This integrated platform of compressed fluid extraction technologies of low-environmental impact was designed in order to produce increases of solvent polarity using non-toxic solvents. The process involved the following steps:(1) supercritical fluid extraction (SFE) using supercritical carbon dioxide (ScCO2); (2) gas expanded liquids (GXL) using 75% ethanol and 25% ScCO2 (v/v) and; (3) pressurized liquid extraction (PLE) using water. Extraction conditions were optimized using response surface methodology (RSM) and kinetic studies. Extraction yield, antioxidant activity as well as contents of total phenols, carotenoids, proteins and sugars were the studied response variables. High performance liquid chromatography coupled to evaporative light-scattering detector (HPLC-ELSD) analyses of the fractions revealed that triacylglycerols were mainly extracted by SFE. Lutein and β-carotene were the main pigments identified in the extracts by HPLC coupled to diode array and mass spectrometry detectors (HPLC-DAD-MS/MS), which were preferentially extracted in the GXL step. Polar compounds such as proteins and sugars remained predominantly in the residue. Therefore, the green downstream platform developed in this study for valorization of the microalgae biomass, is able to produce different fractions with potential application in the food, pharmaceutical and cosmetic industries. © 2017 Elsevier B.V.

Gilbert-Lopez B.,Institute of Food Science Research CIAL UAM CSIC | Barranco A.,Institute of Food Science Research CIAL UAM CSIC | Herrero M.,Institute of Food Science Research CIAL UAM CSIC | Cifuentes A.,Institute of Food Science Research CIAL UAM CSIC | Ibanez E.,Institute of Food Science Research CIAL UAM CSIC
Food Research International | Year: 2016

Two novel extraction techniques, pressurized liquid extraction (PLE) and microwave-assisted solvent extraction (MAE) have been evaluated for the recovery of bioactive compounds from Phaeodactylum tricornutum. Microalga P. tricornutum is rich in polyunsaturated fatty acids (PUFAs), such as EPA, and has a high content of the carotenoid fucoxanthin, which is a valuable pigment with several biological activities. Cells were disrupted at high pressure and then freeze-dried as a previous step to extraction. Additionally, only green solvents as water and ethanol (EtOH) - and mixtures of them - were used. For comparison purposes, the same response variables were considered in both processes: extraction yield (% w/w), total phenolic content (Folin-Ciocalteu assay), total carotenoids and chlorophylls, and antioxidant activity (ABTS assay, expressed as TEAC value). Factorial experimental designs were employed for both PLE and MAE optimization, being %EtOH in water and temperature the common experimental factors. Extraction time was also a factor considered for optimization in MAE. A detailed chemical characterization of pigments was performed by HPLC-DAD-MS/MS (high performance liquid chromatography-diode array detector-mass spectrometry), being fucoxanthin the main compound extracted. Optimum extraction conditions were 50. °C, 100% EtOH, 20. min for PLE, while optimum conditions for MAE were 30. °C, 100% EtOH and 2. min. Both technologies extract fucoxanthin as a main compound but higher recoveries were achieved using PLE due to a higher extraction yield. In addition, both MAE and PLE extracts contained different lipid classes potentially enriched in EPA, given an added-value to the extracts. © 2015.

Loading Institute of Food Science Research CIAL UAM CSIC collaborators
Loading Institute of Food Science Research CIAL UAM CSIC collaborators