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

• Type: Article in International Scientific Journal
• Date: 2010

Authors

R. D. Villanueva (Author) FEUP; A. M. M. Sousa (Author) FEUP; M. P. Gonçalves (Author) FEUP; M. Nilsson (Author) Other; L. Hilliou (Author) FEUP

Journal

Title: Journal of Applied Phycology

Vol. 22 No. 2

Pages: 211-220

ISSN: 0921-8971

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 40 Citations

ISI Web of Science

Scopus - 59 Citations

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Physical sciences

Other information

Authenticus ID: P-003-7W0

DOI: 10.1007/s10811-009-9444-7

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific