Alginate industrial waste streams as a promising source of value-added compounds valorization

Structural and functional properties of alginate obtained by means of high hydrostatic pressure-assisted extraction

“…Seaweeds A. nodosum and S. latissima were pre-treated using HPP and alginate extracted using the method described by Bojorges et al, 2022 to yield AHP and SHP alginate samples, respectively. Briefly, samples were dispersed in water, individually packed in sterile polyethylene bags, and heat-sealed using a liquid:solid ratio of 1:25 (wt.).…”

“…Based on previous literature in which the effect of HPP pre-treatment on polysaccharide extraction was optimized to reach higher extraction yields (Duan, Yan, Azarakhsh, Huang, & Wang, 2022), the samples were pressurized at 350 MPa, for 5 min at 20 ± 2 • C. The pressure level, pressurization time, and temperature were automatically controlled. After completing the pre-treatment, the samples were removed from the container and then submitted to the conventional extraction protocol, as previously described by Bojorges et al, 2022. Alginate extracts from A. nodosum and S. latissima were also obtained using the conventional protocol (without HPP pre-treatment; ACV and SCV, respectively), and commercial sodium alginate (COM; Sigma-Aldrich, PHR1471, Madrid, Spain) was further used for comparative purposes.…”

“…The carbohydrate content and sugar composition of the fractions were determined in triplicate after acid methanolysis according to Bojorges et al, 2022, using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) with a Dionex ICS-6000 (ThermoFisher). In brief, the dry samples were incubated with 2 M HCl in dry methanol (1 mg/mL) at 100 • C for 5 h. Subsequently, samples were neutralized with pyridine, dried under a stream of air, and further hydrolyzed with 2 M TFA for 1 h at 120 • C. The samples were air-dried again and dissolved in water.…”

“…Generally, the alginate extraction process involves an acid pretreatment to remove pigments, carbohydrates, and low molecular weight compounds. Then, an alkaline extraction is performed, followed by solid/liquid separation, drying, and milling, to produce high-quality alginate (Bojorges, Fabra, López-Rubio, & Martínez-Abad, 2022). However, some alternative and novel protocols have been proposed in the last decade (Gomez et al, 2020;Ummat, Sivagnanam, Rajauria, O'Donnell, & Tiwari, 2021;Yang et al, 2022), such as ultrasoundassisted extraction (Flórez-Fernández, Domínguez, & Torres, 2019), enzyme-assisted extraction (Borazjani, Tabarsa, You, & Rezaei, 2017), microwave-assisted extraction (Okolie, Mason, Mohan, Pitts, & Udenigwe, 2020), subcritical water extraction (Saravana, Cho, Woo, & Chun, 2018), and supercritical fluid extraction (Balboa, Moure, & Domínguez, 2015) with the aim of causing microstructural modifications in the treated seaweeds, favoring their extractability (Abka Khajouei et al, 2021).…”

Stabilization Activity of Kelp Extract in Ethylene–Propylene Rubber as Safe Packaging Material

“…The wide spread of Ascophyllum nodosum in different types of forests [ 32 ] and the ease of harvesting these seaweeds [ 33 ] indicate commercial availability and ready access [ 34 , 35 ]. The brown seaweeds, including Ascophyllum nodosum , contain preponderantly alginic acid and alginates [ 36 ] as active elements having antioxidant properties [ 37 ]. Active components existing in the extracts act successfully as biostimulators [ 38 ] because of their contributions as growing agents and antioxidant preventers.…”