<i>Gracilaria gracilis</i> (Gracilariales, Rhodophyta) from Dakhla (Southern Moroccan Atlantic Coast) as Source of Agar: Content, Chemical Characteristics, and Gelling Properties
Zahira Belattmania,
Sanaa Bhaby,
Amal Nadri,
Khaoulaa Khaya,
Fouad Bentiss,
Charafeddine Jama,
Abdeltif Reani,
Vitor Vasconcelos,
Brahim Sabour
Affiliations
Zahira Belattmania
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Sanaa Bhaby
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Amal Nadri
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Khaoulaa Khaya
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Fouad Bentiss
Laboratory of Catalysis and Corrosion of Materials, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Charafeddine Jama
Materials and Transformations Unit, University of Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET, F-59000 Lille, France
Abdeltif Reani
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Vitor Vasconcelos
CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal
Brahim Sabour
Phycology, Blue Biodiversity and Biotechnology RU, Laboratory of Plant Biotechnology, Ecology and Ecosystem Valorization—CNRST Labeled Research Unit N°10, Faculty of Sciences, University Chouaib Doukkali, P.O. Box 20, 24000 El Jadida, Morocco
Agar is a sulfated polysaccharide extracted from certain marine red algae, and its gel properties depend on the seaweed source and extraction conditions. In the present study, the seaweed Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Moroccan Atlantic Coast) was investigated for its agar content, structure, and gel properties. The agar yields of G. gracilis were 20.5% and 15.6% from alkaline pretreatment and native extraction, respectively. Agar with alkaline pretreatment showed a better gelling property supported by higher gel strength (377 g·cm−2), gelling (35.4 °C), and melting (82.1 °C) temperatures with a notable increase in 3,6-anhydro-galactose (11.85%) and decrease in sulphate (0.32%) contents. The sulfate falling subsequent to alkaline pretreatment was verified through FT-IR spectroscopy. The 13C NMR spectroscopy showed that alkaline-pretreated agar has a typical unsubstituted agar pattern. However, native agar had a partially methylated agarose structure. Overall, this study suggested the possibility of the exploitation of G. gracilis to produce a fine-quality agar. Yet, further investigation may need to determine the seasonal variability of this biopolymer according to the life cycle of G. gracilis.
