Production and properties of agar from the invasive marine alga, Gracilaria vermiculophylla (Gracilariales, Rhodophyta)

Content Provider	Semantic Scholar
Author	Villanueva, Ronald D. Sousa, A. M. M. Gonçalves, Maria P. Nilsson, Måns Hilliou, Loic
Copyright Year	2009
Abstract	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.
Starting Page	211
Ending Page	220
Page Count	10
File Format	PDF HTM / HTML
DOI	10.1007/s10811-009-9444-7
Volume Number	22
Alternate Webpage(s)	https://personalpages.manchester.ac.uk/staff/mathias.nilsson/JApplPhycol_2010_22_211.pdf
Journal	Journal of Applied Phycology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article