Microalgae are an extremely diverse group of microscopic organisms, representing one of Earth's oldest forms of life. Due to their high nutritional value, especially in terms of proteins, lipids, and carbohydrates, microalgae are used as a source of nutrients and bioactive compounds for food and feed applications. Moreover, microalgae extracts are frequently part of the composition of cosmetics like face and skin care products with anti-aging, refreshing/regenerating, and anti-irritant properties acting as thickening, water-binding, and antioxidant agents. However, the components must be extracted from microalgae to be used in food, feed, and cosmetics applications. Conventional methods based on solvents are usually used for the extraction of components from microalgae, but they have some inherent limitations such as low efficiency (extraction yield), selectivity, high solvent consumption, and long extraction time.

Pulsed electric field (PEF) is a promising alternative to conventional extraction for the enhancement of the selective extraction of components from microalgae. PEF is a technique that applies electrical pulses usually at high voltages and short durations to a product placed between two electrodes. These electrical pulses affect microalgae's temporary or permanent intracellular membrane structures, resulting in pore formation. The extraction efficiency of PEF can be affected by some critical factors such as electric field strength, pulse shape, treatment time, polarity, and temperature. For this reason, AQUABIOPROFIT evaluated the extraction efficiency of PEF-assisted extraction combined with two different solvents for the recovery of bioactive compounds from two microalgae species (Tetraselmis chuii and Phaeodactylum tricornutum). The study demonstrated that PEF may be a promising alternative for enhancing the selective extraction of antioxidant bioactive compounds from microalgae, which could be interesting for industrial upscaling.

Read more about the principles and the benefits of applying PEF as a mild technology for the extraction of bioactive compounds from microalgae in the scientific article from AQUABIOPROFIT partners (Nofima, and Universitat de Valencia): Kokkali et al. (2020), Improved Extraction Efficiency of Antioxidant Bioactive Compounds from Tetraselmis chuii and Phaedoactylum tricornutum Using Pulsed Electric Fields