Application of Pulsed Electric Fields and High-Pressure Homogenization in Biorefinery Cascade of C. vulgaris Microalgae

Abstract

In this study, a cascaded cell disintegration process, based on pulsed electric fields (PEF - 20 kV/cm, 100 kJ/kgSUSP.) and high-pressure homogenization (HPH - 150 MPa, 5 passes) was designed for the efficient and selective release of intracellular compounds (water-soluble proteins, carbohydrates, and lipids) from C. vulgaris suspensions during extraction in water (25 °C, 1 h) and ethyl acetate (25 °C, 3 h). Recovery yields of target compounds from cascaded treatments (PEF + HPH) were compared with those observed when applying PEF and HPH treatments individually. Particle size distribution and scanning electron microscopy analyses showed that PEF treatment alone did not induce any measurable effect on cell shape/structure, whereas HPH caused complete cell fragmentation and debris formation, with an undifferentiated release of intracellular matter. Spectra measurements demonstrated that, in comparison with HPH alone, cascaded treatments increased the selectivity of extraction and improved the yields of carbohydrates and lipids, while higher yields of water-soluble proteins were measured for HPH alone. This work, therefore, demonstrates the feasibility of sequentially applying PEF and HPH treatments in the biorefinery of microalgae, projecting a beneficial impact in terms of process economics due to the potential reduction of the energy requirements for separation/purification stages.

Cell disruption of microalgae: advances and perspectives

“…The cell disruption of microalgae is considered a critical step in the processing of algal macromolecules (CARULLO et al, 2022;GÜNERKEN et al, 2015), allowing the access of extraction agents into the cells to separate metabolic contents such as carbohydrates, proteins, lipids, vitamins, and other minor compounds. The most significant factors determining cell wall strength are wall thickness, structure, and chemical composition, which confer unique features to the cells of different microalgal species.…”

Decay of Trichomes of Arthrospira platensis After Permeabilization Through Pulsed Electric Fields (PEFs) Causes the Release of Phycocyanin

“…During the pulse, spontaneously formed hydrophobic pores, grow and, above a certain pore size, become hydrophilic and thus permeable for various cellular substances (Saulis, 2010). A PEF has been recently investigated in the context of biorefinery approaches for different microalgae species (Buchmann and Mathys, 2019;Leonhardt et al, 2020;Papachristou et al, 2021;Carullo et al, 2022). Compared to other cell disruption methods such as bead milling, it was claimed that a PEF enables selective cell permeabilization for water-soluble substances while preserving cell structure (Goettel et al, 2013;Postma et al, 2016;Lam et al, 2017b).…”

Effect of aqueous ozone treatment on the reduction of chlorpyrifos and physicochemical and microbial qualities of cucumber (Cucumis sativusL.): Process modeling and optimization

“…The luminance or brightness component, L*, has a value between 0 and 100 (from black to white). The two chromatic components are the a* and b* values, which range from À120 to 120 (from green to red) and À120 to 120 (from blue to yellow), respectively(Carullo et al, 2022;…”