Extraction of Antioxidant Compounds and Pigments from Spirulina (Arthrospira platensis) Assisted by Pulsed Electric Fields and the Binary Mixture of Organic Solvents and Water

Francisco J Martí-Quijal,Francisco J Barba,Houda Berrada,Noelia Pallarés,Emilia Ferrer,Yuthana Phimolsiripol,Francesc Ramon-Mascarell

doi:10.3390/app11167629

Abstract

The application of pulsed electric fields (PEF) is an innovative extraction technology promoting cell membrane electroporation, thus allowing for an efficient recovery, from an energy point of view, of antioxidant compounds (chlorophylls, carotenoids, total phenolic compounds, etc.) from microalgae. Due to its selectivity and high extraction yield, the effects of PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction at different times (5–180 min) and with different solvents (ethanol (EtOH)/H2O, 50:50, v/v; dimethyl sulfoxide (DMSO)/H2O, 50:50, v/v) were evaluated in order to obtain the optimal conditions for the extraction of different antioxidant compounds and pigments. In addition, the results obtained were compared with those of a conventional treatment (without PEF pre-treatment but with constant shaking). After carrying out the different experiments, the best extraction conditions to recover the different compounds were obtained after applying PEF pre-treatment combined with the binary mixture EtOH/H2O, 50:50, v/v, for 60–120 min. PEF extraction was more efficient throughout the study, especially at short extraction times (5–15 min). In this sense, recovery of 55–60%, 85–90%, and 60–70% was obtained for chlorophylls, carotenoids, and total phenolic compounds, respectively, compared to the maximum total extracted amount. These results show that PEF improves the extraction yield of antioxidant bioactive compounds from microalgae and is a promising technology due to its profitability and environmental sustainability.

Highlights

Over the last decade, several research studies have evaluated the use of microalgae as a source of nutrients and bioactive compounds
Microalgae are becoming increasingly relevant, especially for their composition, since they are a source of high-added-value compounds [5], such as carotenoids, chlorophylls, and other pigments [6], and polyunsaturated fatty acids [7,8]
There is a need for innovative approaches such as pulsed electric fields (PEF) that affect the quality of the extracted compounds to a lesser extent and can be applied in a continuous flow to obtain higher extraction efficiency rates, minimize the use of solvents, and be a more efficient and sustainable extraction alternative [10,11]

Summary

Introduction

Several research studies have evaluated the use of microalgae as a source of nutrients and bioactive compounds. This is due to a growing interest in the development of new foods that provide health benefits and that meet basic energy and nutritional requirements [1,2]. It is preferred that functional foods have a natural origin, such as from plants, algae and/or microalgae. Conventional extraction of antioxidant bioactive compounds from microalgae is often carried out using solvents and using dry biomass [9]. There is a need for innovative approaches such as pulsed electric fields (PEF) that affect the quality of the extracted compounds to a lesser extent and can be applied in a continuous flow to obtain higher extraction efficiency rates, minimize the use of solvents, and be a more efficient and sustainable extraction alternative [10,11]

Objectives

Methods

Results