Centre for Ecology, Evolution and Environmental Changes

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Publications

Biochemical study of attached macroalgae from the Madeira Archipelago and beach-cast macroalgae from the Canary Islands: multivariate analysis to determine bioresource potential

Publication . Nunes, Nuno; Valente, Sofia; Ferraz, Sónia; Barreto, Maria Carmo; Carvalho, Miguel Â. A. Pinheiro de

Fifteen attached macroalgae from the Madeira Archipelago, comprising three green, three red and nine brown algal species, as well as two beach-cast macroalgal samples, collected along the north shore of Gran Canaria, were assessed for their biochemical properties. The anal ysis included the determination of total minerals, total carbohydrates, protein, lipids, chlorophyll a, total carote noids, total phenolic content, fucoxanthin and phycobilins (allophycocyanin, phycocyanin and phycoerythrin). The results showed a high variability of biochemical composi tion, allowing for the targetting of specific bioresources for particular purposes, including functional foods. This work provides the foundation for a biorefinery strategy implementation plan, for which specific macroalgae may be tar geted for valuable and beneficial compounds

2020Journal article

Open access

Constructing ethanol-derived bioactive extracts using the brown seaweed Zonaria tournefortii (J.V.Lamouroux) Montagne performed with Timatic extractor by means of response surface methodology (RSM)

Publication . Nunes, N.; Valente, S.; Ferraz, S.; Barreto, Maria Carmo; Carvalho, M.A.A. Pinheiro de

Understanding the biochemical and antioxidant composition and capacity of a target biomass is the first step to its selectivity as functional food which can enhance the ability to promote health by reducing the risk of chronic diseases. The main purpose of this work was to employ response surface methodology (RSM) to determine the effect of the independent variables, % of ethanol (50–96%), time of sonication (0–20 min), and number of extraction cycles (6–18 cycles) in the primary extract of brown seaweed Zonaria tournefortii, studying the yield variation of some bioactive compounds, assessing the potential of these bioextracts to integrate as a natural additives or supplements in the functional food industry. The extractions were performed employing “Green Chemistry” techniques executed with the Timatic extractor, which applied pressurized ethanol solution at a maximum pressure of 8.5 bar through milled dehydrated biomass in the extraction vessel. Several parameters were assessed in the primary bioactive extract which included extract yield (11.56–28.49 g (100 g)−1 dw), total chlorophyll content (0.14–1.42 g (100 g)−1 dw), total carotenoid content (0.35–0.80 g (100 g)−1 dw), total fucoxanthin content (0.04–0.13 g (100 g)−1 dw), total phenolic content (3.58–5.84 g (100 g)−1 dw), total flavonoid content (0.22–4.70 g (100 g)−1 dw), DPPH (56.05–76.45%), and reducing activity (3.83–6.04 g (100 g)−1 dw). A second objective was to determine the suitability of the residue for subsequent extraction of valuable compounds such as fucoidan (4.87 to 6.59 g (100 g)−1 dw) and cellulose (18.88 to 20.27 g (100 g)−1 dw), implementing the first step to a biorefinery strategy, using a cascade approach.

2019Journal article

Open access