23RD INTERNATIONAL SEAWEED SYMPOSIUM, JEJU 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) N. Nunes 1,2 & S. Valente 2 & S. Ferraz 1 & Maria Carmo Barreto 3 & M.A.A. Pinheiro de Carvalho 1 Received: 7 June 2019 /Revised and accepted: 22 October 2019 # Springer Nature B.V. 2019 Abstract 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. Keywords Functional food . Bioactive extract . Biorefinery . Phaeophyceae . Fucoidan Introduction Intensive research is conducted worldwide to increase knowl- edge concerning the integration and use of non-conventional food sources, of both terrestrial and marine origin, to improve the nutritional quality of food (Kumar et al. 2011). The under- standing of the biochemical composition and antioxidant ca- pacity of the target biomass is the first step to its selectivity as a functional food, promoting health benefits and reducing the risk of chronic diseases. Seaweeds represent an increasingly exploited excellent raw material for nutrients, food ingredi- ents, and bioactive compounds (Kılınç et al. 2013). Intensive research concerning biorefinery strategy implementation to seaweed biomass has been published, in which this resource is introduced in a cascade extraction for multiple product pro- duction, increasing the biomass usability and reducing waste. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10811-019-01973-9) contains supplementary material, which is available to authorized users. * N. Nunes nuno.nunes@staff.uma.pt 1 ISOPlexis Genebank, Faculty of Life Sciences, University of Madeira, Campus da Penteada, 9050-290 Funchal, Madeira, Portugal 2 UBQ II, Unidade de Bioquímica, Lda. Rua Visconde de Anadia, Edifício Anadia 5° Andar CC, 9050-020 Funchal, Madeira, Portugal 3 cE3c–Centre for Ecology, Evolution and Environmental Changes/ Azorean Biodiversity Group and Faculty of Sciences and Technology, University of Azores, 9501-801 Ponta Delgada, Portugal https://doi.org/10.1007/s10811-019-01973-9 / Published online: 28 November 2019 Journal of Applied Phycology (2020) 32:2321–2333