Characterization of Carrageenan Extracted from Hypnea bryoides in Oman

• Published in: Marine biotechnology (New York, N.Y.) Vol. 13; no. 5; pp. 893 - 899
• Main Authors: Al-Alawi, Ahmed Ali, Al-Marhubi, Insaaf Mohammed, Al-Belushi, Mohammed Said Moosa, Soussi, Bassam
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01.10.2011; Springer Nature B.V
• Subjects: alcohols; Algae; alkali treatment; Analysis; Biomedical and Life Sciences; Biotechnology; Breweries; Carbohydrates; Carrageenan; Carrageenan - chemistry; Carrageenan - metabolism; chemistry; Chromatography, Gel; Engineering; Food; Fourier transform infrared spectroscopy; Freshwater & Marine Ecology; Hypnea; Investigations; kappa carrageenan; Life Sciences; lipid content; Lipids; macroalgae; Marine; Medical and Health Sciences; Medicin och hälsovetenskap; metabolism; Microbiology; Molecular weight; Oceans and Seas; Oman; Original Article; potassium chloride; Proteins; Raw materials; Rheology; Rhodophyta; Rhodophyta - metabolism; Sodium hydroxide; Studies; Transition temperatures; Wind; Zoology; Oman; Seaweed; Phycocolloids; Algae; FTIR
• ISSN: 1436-2228; 1436-2236; 1436-2236
• DOI: 10.1007/s10126-010-9350-7

Carrageenophyte red seaweed from Oman, Hypnea bryoides, extracted using three different processes: an aqueous, a mild alkaline, and a more vigorous alkaline extraction was investigated. The resulting extract precipitated by alcohol was subject to chemical and rheological measurements. The total carbohydrate [ranged from 36.78 to 41.65 g/100 g], and ash [39.04 to 43.11 g/100 g] were the most abundant components in H. bryoides and contrary to the two, lipid content was found at a minimum [ranging from 2.95 to 3.38 g/100 g]. Alkali treatment with NaOH allowed complete conversion of kappa (κ) carrageenan form as detected by FTIR analysis. Total yield by alkali treatments gave higher yields (33%) compared with aqueous treatments (12%). However, subsequent aqueous treatment produced mixed carrageenan (μ and κ) with higher molecular weight compared with the alkali treatments which produced single carrageenan form (κ) with molecular weight of 4.1 × 105 Da. The effects of thermal history on gel–sol and sol–gel transition were investigated by differential scanning calorimeter (DSC) and rheology on a pure sample and 1.5% κ-carrageenan mixture added with 30 mM KCl. Transition temperatures from DSC and rheology showed comparable results and were in good agreement with those previously reported.