Pulsed electric field-assisted extraction of carotenoids from Chlorella zofingiensis

The present work aimed to evaluate the use of PEF as a pretreatment to carotenoid and chlorophyll extraction from two different C. zofingiensis biomasses, green (non-stressed) and orange (stressed). PEF treatment was performed by varying the electric field strength (15, 20, 25 kV/cm) and the treatment time (30, 75, 150 μs). The effect of incubation in a pH 7 buffer for 24 h after PEF and before extraction was also evaluated. The application of an intermediate intensity combined with higher number of pulses (20 kV/cm with 50 pulses) was sufficient to promote the extraction, yielding the highest contents of carotenoids and chlorophylls. The incubation promoted higher extraction yields for treatments performed with shorter treatment times and with mild electric field strengths. Overall, the findings of this study suggest that the application of PEF combined with ethanol could represent a suitable approach for the extraction of carotenoids and chlorophylls from Chlorella zofingiensis biomass.