Optimization of operating parameters for polyphenol extraction from lipid extracted microalgae

Microalgae are a promising source of lipids for biodiesel production. In order to enhance the economic value of this biodiesel feedstock, it is necessary for production of valuable compounds from the microalgae after lipid extraction. In this paper, value added product, polyphenol, extraction from lipid extracted microalgae (LEA) using organic solvents and binary mixture of water-ethanol was investigated. To enhance the productivity, extraction solvent, ethanol concentration, extraction temperature and time were evaluated to maximize the polyphenols extraction from defatted Tetraselmis sp. Ethanol and water was found to be effective in extracting, when evaluating the impact of the organic solvent on the polyphenol extract. Ethanol concentrations and extraction temperature were major influencing parameters (p<0.05) and extraction yield increased with increase in both factors. Extraction yield showed an maximum value of 3.12 mg GAE/g at 70% ethanol, 90C and 20 min. Although Tetraselmis sp was pretreated by hexane to remove lipid, it still contains relatively high level of polyphenols and the optimum conditions determined for polyphenol extraction are useful in LEA by binary mixture of water-ethanol.