Microwave-Assisted Alginate Extraction from Portuguese Saccorhiza polyschides – Influence of Acid Pretreatment

Brown seaweeds are abundant in Portuguese coastline
and represent an almost unexploited marine economic resource. One
of the most common species, easily available for harvesting in the
northwest coast, is Saccorhiza polyschides grows in the lowest shore
and costal rocky reefs. It is almost exclusively used by local farmers
as natural fertilizer, but contains a substantial amount of valuable
compounds, particularly alginates, natural biopolymers of high
interest for many industrial applications.
Alginates are natural polysaccharides present in cell walls of
brown seaweed, highly biocompatible, with particular properties that
make them of high interest for the food, biotechnology, cosmetics
and pharmaceutical industries. Conventional extraction processes are
based on thermal treatment. They are lengthy and consume high
amounts of energy and solvents. In recent years, microwave-assisted
extraction (MAE) has shown enormous potential to overcome major
drawbacks that outcome from conventional plant material extraction
(thermal and/or solvent based) techniques, being also successfully
applied to the extraction of agar, fucoidans and alginates. In the
present study, acid pretreatment of brown seaweed Saccorhiza
polyschides for subsequent microwave-assisted extraction (MAE) of
alginate was optimized. Seaweeds were collected in Northwest
Portuguese coastal waters of the Atlantic Ocean between May and
August, 2014. Experimental design was used to assess the effect of
temperature and acid pretreatment time in alginate extraction.
Response surface methodology allowed the determination of the
optimum MAE conditions: 40 mL of HCl 0.1 M per g of dried
seaweed with constant stirring at 20ºC during 14h. Optimal acid
pretreatment conditions have enhanced significantly MAE of
alginates from Saccorhiza polyschides, thus contributing for the
development of a viable, more environmental friendly alternative to
conventional processes.

• Mário Silva
• Filipa Gomes
• Filipa Oliveira
• Simone Morais
• Cristina Delerue-Matos

• Acid pretreatment
• Alginate
• Brown seaweed
• Microwave-assisted extraction
• Response surface methodology.

[1] I. Sousa-Pinto, The seaweed resources of Portugal, A.T. Critchley, M.
Ohno (Eds.), Seaweed resources of the world, Japan International
Cooperation Agency, Yokosuka (1998), pp. 176–184.
[2] Marcia R. Torres, Alessandra P. A. Sousa, Eduardo A. T. Silva Filho,
Dirce F. Melo, Judith P. A. Feitosa, Regina C. M. de Paulab, Maria G. S.
Lima, Extraction and physicochemical characterization of Sargassum
vulgare alginate from Brazil, Carbohydrate Research, 342 (2007) 2067–
2074.
[3] Norton, T.A. & Burrows, E.M. (1969). Studies on marine algae of the
British Isles, chapter 7, Saccorhiza polyschides (Lightf.) Batt. Br.
Phycol. J., 4: 19–53.
[4] V. García-Ríos, E. Ríos-Leal, D. Robledo, Y. Freile-Pelegrin,
“Polysaccharides composition from tropical brown seaweeds”,
Phycological Research, 60 (2012) 305-315.
[5] DJ McHugh; Production, properties and uses of alginates. DJ McHugh
(Ed.), FAO Fisheries Technical Paper No. 288, Food and Agriculture
Organization of the United Nations, Rome (1987), pp. 58–115.
[6] Caroline Bertagnolli, Ana Paula D.M. Espindolab, Sirlei Jaiana
Kleinübinga, Ljubica Tasicb, Meuris Gurgel Carlos da Silva,
“Sargassum filipendula alginate from Brazil: Seasonal influence and
characteristics”, Carbohydrate Polymers, 111 (2014), 619–623.
[7] P. Vauchel, K. Le Roux, R. Kaas, A. Arhaliass, R. Baron, J. Legrand,
“Kinetics modeling of alginate alkaline extraction from Laminaria
digitata”, Bioresource Technology, 100 (2009), 1291-1296.
[8] Ian J. Miller, “Alginate composition of some New Zealand brown
seaweeds”, Phytochemistry, 41 (1996), 1315–1317.
[9] Marie Pascaline Rahelivao, Hanta Andriamanantoanina, Alain
Heyraudb, Marguerite Rinaudob, “Structure and properties of three
alginates from Madagascar seacoast alge”, Food Hydrocolloids, 32
(2013), 143–146.
[10] Hanta Andriamanantoanina, Marguerite Rinaudob, “Characterization of
the alginates from five madagascan brown algae”, Carbohydrate
Polymers, 82 (2010), 555–560.
[11] University of Oslo, department of Chemistry (online).
http://www.mn.uio.no/kjemi/english/people/aca/bony/research/alginate.h
tml (Accessed 12 November, 2014).
[12] Vivekananda Mandal, Yogesh Mohan, S. Hemalatha, “Microwave
Assisted Extraction – An Innovative and Promising Extraction Tool for
Medicinal Plant Research”, Pharmacognosy Reviews, Vol 1, Issue 1,
Jan-May, 2007.
[13] A.M.M. Sousa, V.D. Alves, S. Morais, C. Delerue-Matos, M.P.
Gonçalves, “Agar extraction from integrated multitrophic aquacultured
Gracilaria vermiculophylla: Evaluation of a microwave-assisted process
using response surface methodology”, Bioresource Technology, 101
(2010), 3258–3267.
[14] R.M. Rodriguez-Jasso, S.I. Mussatto, L. Pastrana, C.N. Aguilar, J.A.
Teixeira, “Microwave-assisted extraction of sulfated polysaccharides
(fucoidan) from brown seaweed”, Carbohydrate Polymers, 86 (2011)
1137-1144.
[15] Filipa Gomes, Filipa Oliveira, Manuela Correia, Simone Morais,
Cristina Delerue-Matos, “Microwave-Assisted Extraction of Alginate
from Portuguese Brown Algae”, in Proc. ChemPor 2014 - XII Chemical
and Biological Engineering Conference, Porto, September 2014.
[16] Perez, R., Kaas, R., Campello, F., Arbault, S.--, Barbaroux, O., 1992. La
culture des algues marines dans le monde. IFREMER, Plouzané, -
France.
[17] Montgomery, Douglas C. “Design and Analysis of Experiments (7th
edition)”, John Wiley & Sons, 2009.
[18] Paula Paíga, Simone Morais, Teresa Oliva-Teles, Manuela Correia,
Cristina Delerue-Matos, et al., Determination of Ochratoxin A in Bread:
Evaluation of Microwave-Assisted Extraction Using an Orthogonal
Composite Design Coupled with Response Surface Methodology, Food
Bioprocess Technology 6 (2013) 2466–2477.