Continuous pressurized extraction versus electric fields-assisted extraction of cyanobacterial pigments

Abstract

Cyanobacteria pigments, in special carotenoids and phycobiliproteins, are usually used in industry as raw extracts, although there is still no standard methodology for their extraction. For the co-extraction of carotenoids and phycobiliproteins from the marine cyanobacterium Cyanobium sp., a continuous pressurized solvent extraction (CPSE) system and an electric fields-assisted extraction system based in ohmic heating were optimized using Central Composite Designs, with three factors each: time (t), temperature (T) and, flow (f) for CPSE; and time, temperature and frequency (F) for ohmic heating. The content of pigments and the antioxidant capacity of extracts were evaluated. All tested factors seem to influence the extraction of pigments in different ways: a high temperature (70 • C) had a positive impact on the extraction rate in both methods, while the influence of time depended on the extraction principle. Flow and frequency affected directly the extraction efficiency and these methods are indeed suitable for cyanobacterial pigments extraction, achieving good extraction results. Optimal conditions for co-extraction of carotenoids and phycobiliproteins in CPSE were T = 70 • C, t = 20 min and f = 1.5 mL min − 1 , and for ohmic heating they were T = 70 • C, t = 5 min and F = 20 kHz. Both, CPSE and ohmic heating systems allowed obtaining better extraction yields when compared with a previously optimized extraction method (homogenization), used here as a reference. However, ohmic heating was the best methodology for pigments co-extraction from Cyanobium sp.

Identifying Key Environmental Indicators in the Assessment of the Proof-of-Concept in Pigment Production from the Marine Cyanobacterium Cyanobium sp.

“…Three processes were considered depending on the production volume and reactor type. The first was the available results of the laboratory scale optimisation process (20 L), grown in an indoor growth chamber [15,16] and carried out at CIIMAR, Porto (Portugal); the second was at a demonstration scale, in a flat-panel reactor (140 L), based on the system proposed for Arthrospira platensis by Nwoba et al [35]; and the third scenario is an industrial-scale open-air tubular bioreactor (100 m 3 ) proposed by Pereira et al [36] for Tetraselmis sp. (microalgae) and Lopes et al [17] for Synechocystis sp.…”

“…The laboratory-scale process was based on the proposed optimized process of Cyanobium sp. [15,16]. The cultivation was performed in a 20 L polycarbonate cylindrical reactor, the pre-inoculum being performed in a 2 L borosilicate round flask.…”

“…Comprehensive data on the cyanobacterium cultivation, harvesting and extraction, as well as the amount of chemicals (nutrients, solvents), water supply and waste volume, and electricity consumption, were obtained through laboratory-scale experiments [15,16]. Tables 1-3 include the Life Cycle Inventory considered for the laboratory-scale, demonstrationscale and industrial-scale processes.…”

“…Its potential was first proposed as a producer of some bioactive compounds, such as hierridin B and C, with antitumour and antimalarial activities [10][11][12], however, the content of such compounds is extremely low, which reduces its interest in favour of the synthetic route [13]. On the other hand, the production and extraction processes of pigments with antioxidant and anti-inflammatory properties have been investigated [14][15][16]. Specifically, the process was optimised by focusing on two bioactive pigment extracts from the same biomass, one targeting carotenoids and the other phycobiliproteins.…”

Emergent Proteins-Based Structures—Prospects towards Sustainable Nutrition and Functionality

“…In particular, electric-field based technologies, such as OH and PEF showed promising results with extraction of compounds, including proteins from microalgae biomass [61][62][63][64]. More recently, novel perspectives about the influence of electric fields on protein structure were unveiled.…”