Molar mass and rheological characterisation of an exopolysaccharide from Pediococcus damnosus 2.6

Summary, in English

The molar mass and theological properties of an exopolysaccharide (EPS) from Pediococcus damnosus 2.6 were investigated. The molar mass was determined by asymmetrical flow field-flow fractionation coupled with multiangle light scattering and refractive index detection. The EPS was observed to be a flexible chain polymer with a molar mass value of 4 x 10(6) g mol(-1). Heating the sample at 80 degrees C for 10 min caused a shift to lower hydrodynamic radius. The theological behaviour of the EPS was compared to that of a commercial cereal beta-glucan (0.359 x 10(6) g mol(-1)). The maximum storage modulus, G'(max) for EPS solution was lower than that for the cereal beta-glucan at all concentrations, while the relaxation time, t(G'=G") was higher. The G'(max) was reduced on heating the EPS solution at 80 degrees C for 10 min, likely indicating some conformational changes. Three-dimensional models of the polymers revealed some differences in intramolecular hydrogen bonds. The EPS molecule had a ropy nature in solution and this could make it suitable for usage as a thickener in food systems. (c) 2006 Elsevier Ltd. All rights reserved.

• Author: Adele Lambo; Mats Leeman; Karl-Gustav Wahlund; Margareta Nyman; Rickard Öste; Helena Larsson
• Department/s: Division of Food and Pharma; Centre for Analysis and Synthesis; Department of Food Technology, Engineering and Nutrition
• Publishing year: 2007
• Language: English
• Pages: 577-586
• Publication/Series: Carbohydrate Polymers
• Volume: 68
• Issue: 3
• Links: http://dx.doi.org/10.1016/j.carbpol.2006.06.037
• Document type: Journal article
• Publisher: Elsevier
• Topic: Food Engineering; Analytical Chemistry; Nutrition and Dietetics
• Keywords: Pediococcus damnosus 2.6; exopolysaccharide; molar mass; root mean; square radius; loss modulus; polydispersity; storage modulus
• Status: Published
• ISBN/ISSN/Other: ISSN: 0144-8617