Improved Extraction Efficiency of Antioxidant Bioactive Compounds from Tetraselmis chuii and Phaedoactylum tricornutum Using Pulsed Electric Fields.

Marialena Kokkali,María-José Ruiz,Katerina Kousoulaki,Mercedes Taroncher,Francisco J Barba,Francisco J Martí-Quijal

doi:10.3390/molecules25173921

Marialena Kokkali, María-José Ruiz + Show 4 more

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https://doi.org/10.3390/molecules25173921

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Abstract

Pulsed electric fields (PEF) is a promising technology that allows the selective extraction of high-added value compounds by electroporation. Thus, PEF provides numerous opportunities for the energy efficient isolation of valuable microalgal bioactive substances (i.e., pigments and polyphenols). The efficiency of PEF-assisted extraction combined with aqueous or dimethyl sulfoxide (DMSO) solvents in recovering pigments and polyphenols from microalgae Tetraselmis chuii (T. chuii) and Phaeodactylum tricornutum (P. tricornutum) was evaluated. Two PEF treatments were applied: (1 kV/cm/400 pulses, 3 kV/cm/45 pulses), with a specific energy input of 100 kJ/kg. The total antioxidant capacity (TAC) was positively influenced by the use of DMSO. The highest TAC in the T. chuii culture was achieved at a lower extraction time and electric field than for P. tricornutum. The use of DMSO only improved the polyphenols′ extraction for P. tricornutum, whereas the PEF and extraction time were more important for T. chuii. Carotenoids and chlorophyll a were more efficiently extracted using DMSO, while chlorophyll b levels were higher following aqueous extraction for both microalgae. In P. tricornutum, the TAC and pigment extraction efficiency were in general higher at lower extraction times. It can be concluded that PEF may be a promising alternative for the enhancement of the selective extraction of antioxidant bioactive compounds from microalgae.

Highlights

Over the last years, several research studies have evaluated the potential of microalgae as a source of nutrients and bioactive compounds for food (e.g., Spirulina, Chlorella, Nannochloropsis, etc.) and feed applications
It is known that polyphenols and pigments like carotenoids contribute significantly to the total antioxidant capacity (TAC) of microalgae [18]
The results on the TAC, total phenolics and pigments for T. chuii are summarized in Figure 1a for water and Figure 1b for dimethyl sulfoxide (DMSO), whereas the respective results for P. tricornutum are summarized in Figure 2a for water and Figure 2b for DMSO

Summary

Introduction

Several research studies have evaluated the potential of microalgae as a source of nutrients and bioactive compounds for food (e.g., Spirulina, Chlorella, Nannochloropsis, etc.) and feed applications. Molecules 2020, 25, 3921 costs lead to the need for the development of more efficient and sustainable extraction technology alternatives [8,9,10]. In this sense, it has been shown that the use of pulsed electric fields (PEF), which is a technique consisting of the application of electrical pulses between two electrodes, has several advantages [6].

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