SUPERCRITICAL FLUID EXTRACTION OF MICROALGAE SPIRULINA PLATENSIS. CHEMO-FUNCTIONAL CHARACTERIZATION

摘要

The goal of the present work was to develop clean technologies for the isolation of new functional ingredients from alternative sources such microalgae. Clean technologies were based on the use of supercritical fluids such as carbon dioxide and ethanol as modifier. Both are GRAS (Generally Recognized As Safe) solvents, therefore, both of them can be used in the food industry. In this work, a complete study of the parameters that control supercritical fluid extraction (pressure, temperature, density and use of modifier) was performed. Pressures tested ranged from 78 to 361 bar, temperatures from 26 to 83°C and densities from 0.195 to 0.923g/ml. All experiments were done under an experimental design strategy. The design was done twice, differing in the use of 10% ethanol as co-solvent. The chemical characterization of the extracts was performed using liquid chromatography with Diode Array Detector while the fractions were also functionally characterized by in vitro antioxidant activity assays (using the β-carotene bleaching method). The possibility of the combined used of functional and chemical characterization of the extracts provides a complete information about both, the activities expected and the compounds responsible for such activity.