Abstract
Recovery of intracellular components from microalgae requires a cell disruption step. In recent years, pulsed electric field (PEF) treatment has been discussed to be an efficient alternative to conventional cell disruption techniques, i.e. homogenization or bead milling.
In this work the effect of the main processing parameters of the PEF treatment on the extraction of valuable compounds from microalgae Chlorella Vulgaris was investigated.
Culture of C. vulgaris strain inoculated in TAP-medium, were cultivated in batch 26 L photo-bioreactor. The algae were harvested after 24 days and concentrated up to a final biomass concentration of 40.8 gdw/kg of suspension. PEF experiments at different field strength (E=27-35 kV/cm) and energy input (WT=50-100-150 kJ/kg) were carried out in a laboratory scale continuous flow unit. Determinations of time-conductivity profile as well as quantification of dry matter, carbohydrates, protein content, and total phenolics of the supernatant collected after 1 h extraction, were performed.
Results showed a higher increase of the electrical conductivity of PEF treated suspension, when compared to the untreated samples, as a result of the irreversible electroporation induced by pulse treatment. Moreover, the PEF treatment increased the dry matter content as well as the amount of carbohydrates, proteins and phenolic compounds released into the supernatant from inside the algae cells.
The results obtained from this study demonstrate the potential of PEF for improving extraction yield of valuable compounds from microalgae.
