Browsing by Subject "accelerated solvent extraction"

Microalgae are the most primitive and simple members of plant kingdom, unicellular or colonial and can be found worldwide. Microalgae are promising organism for producing sustainable biomass and microalgae can be used to produce proteins, lipids, colourants, vitamins and carbohydrates to food industry and can be used as feed for animals and source for biofuels. The objective of this study was to select the most effective extraction solvent and develop and optimize an accelerated solvent extraction (ASE) method for microalgal lipids. ASE is an extraction technique that needs only small amounts of solvents and uses elevated temperature and pressure for better extractability. Study had two separated parts; 1. Choosing the best solvent for ASE, 2. Optimizing extraction conditions. Study was made with two freeze dried biomasses; Euglena gracilis and Selenastrum Sp. Choosing an extraction solvent for ASE was made between acetone, ethanol and 2-ethoxyethanol and those were compared for Bligh and Dyer chloroform- methanol-water solvent extraction. Lipid yields were analyzed as total fat as sum of fatty acid methyl esters and fatty acid composition with GC-FID. Overview of lipidclasses was studied with TLC. Tocopherol analysis was made with NP-HPLC-FLD and carotenoids and chlophylls were analyzed with UV-VIS spectroscopy. Optimizing the extraction conditions was made with experimental design program with 2*15 samples in different extraction conditions with ethanol as solvent. Evaluation of results was made by total fat, omega-3 fattyacids EPA and DHA, tocopherol, carotenoid and chlorophyll contents. Optimized extraction conditions were: Temperature 125 ⁰C, Extraction time 11 min, 1 extraction cycle and Pressure 1500 psi. Temperature had the greatest effect on the studied extraction parameters.