Determination of the uronic acid composition of seaweed dietary fibre by HPLC

Abstract

A high-performance liquid chromatographic (HPLC) method is described for determination of the ratio of beta-d-mannuronic acid to alpha-l-guluronic acid (M/G ratio) in dietary fibre of edible seaweeds. Total dietary fibre (TDF) content was determined gravimetrically. The TDF fraction was hydrolysed with 12 m and 1 m H(2)SO(4), then neutralized with AG 4 x 4 resin. The uronic acids were separated in a Tracer Extrasil SAX 5 micro m column (25 cm x 4 mm) at 35 degrees C, with 2 mm KH(2)PO(4) containing 5% methanol as mobile phase at a fl ow rate of 1.5 mL/min. The detection wavelength was UV 210 nm. The chromatographic identifications of beta-d-mannuronic acid and alpha-l-guluronic acid were confirmed by liquid chromatography-mass spectrometry (LC-MS). The method precision was 1.4% for beta-d-mannuronic acid and 3.5% for alpha-l-guluronic acid. The method was used to determine M/G ratio in canned seaweeds (Saccorhiza polyschides and Himanthalia elongata) and in dried seaweeds (H. elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp. and Porphyra sp.).

Nutritional Quality of Edible Parts of Moringa oleifera

“…The content of total dietary fiber was quantified following the gravimetricenzymatic method, with residual protein and residual ash correction (Sánchez-Machado et al 2004a). The ash content was calculated by incineration of the samples at 525°C for 5 h to a constant weight (Association of Official Analytical Chemists (AOAC) 1984).…”

“…To determine the total content of the amino acids, an acid hydrolysis was performed on the proteins (50 mg of the sample was added with 10 ml of HC1 6 N and was heated at 110°C for 24 h). The hydrolyzed product was vacuumed and filtered, and then diluted at 250 ml in a volumetric flask (Sánchez-Machado et al 2003). A 300 μl was oven dried at 60°C all night, and the residue was diluted in 300 μl of a borate buffer through agitation (15 s).…”

Studies on Pharmaceutical and Commercial Significance Amino Acids From Marine Green Algal Species of Caulerpaceae

“…[15] All determinations were performed in triplicate, and the data are shown in terms of mean ± standard deviation (SD).…”

Critical review of elements of plant therapy opposable to excess weight

“…De nombreux polysaccharides ont une activité similaire : polysaccharide d'Oryza sativa (oryzanes), de Glycine soja (glycanes), du Panax ginseng (panaxanes), de l'Eleutherococcus, etc. [1,2,12,24].…”

“…L'AHC inhibe la production par le foie de l'enzyme ATP-citrate lyase, qui joue un rôle clé dans la transformation des sucres en triglycérides et lipoprotéines LDL. Il provoque un ralentissement de la production du stockage des graisses issues du métabolisme des sucres et des protéines [24,28].…”