|Production and properties of agar from the invasive marine alga, Gracilaria vermiculophylla (Gracilariales, Rhodophyta)|Villanueva, R.D.; Sousa, A.M.M.; Gonçalves, M.P.; Nilsson, M.; Hilliou, L. (2010). Production and properties of agar from the invasive marine alga, Gracilaria vermiculophylla (Gracilariales, Rhodophyta). J. Appl. Phycol. 22(2): 211-220. hdl.handle.net/10.1007/s10811-009-9444-7
In: Journal of Applied Phycology. Springer: Dordrecht. ISSN 0921-8971, more
Algae; Gracilaria vermiculophylla (Ohmi) Papenfuss, 1967 [WoRMS]; Marine
Agar; Alkali treatment; Extraction; Gel strength; Gracilaria vermiculophylla ; Invasive alga
|Authors|| || Top |
- Villanueva, R.D.
- Sousa, A.M.M.
- Gonçalves, M.P.
The utilization potential, in terms of agar production, of the invasive alga, Gracilaria vermiculophylla, collected at Ria de Aveiro, northwestern Portugal was investigated. The agar yield ranged from 15% to 33%, with pre-extraction treatment with alkali generally increasing the yield. The gel quality (gel strength and apparent Young’s modulus) was best (>600 g cm-2 and >1,000 kPa, respectively) when alkali treatment with 6% NaOH for 3.5 h was performed. At these pretreatment conditions, the effect of extraction time was also investigated and highest yield and best gel quality were obtained with a 2 h extraction time. By employing these extraction conditions, G. vermiculophylla can be a source of industrial food-grade agar. The structure of agar from G. vermiculophylla was determined through chemical techniques and FTIR and NMR spectrometry. It is mainly composed of alternating 3-linked d-galactose and 4-linked 3,6-anhydro-l-galactose, with methyl substitution occurring at 16–19 mol% of C-6 in 3-linked units and 2–3 mol% of C-2 in 4-linked units. A minor sulfation on C-4 of 3-linked units was also detected; while precursor units (6-sulfated 4-linked galactosyl moieties) were found in the native extract.