Rheological characterization under shear of a fraction of polymer produced via fermentation of whey-related media by Rahnella aquatilis

M. E. Pintado, J. A. Lopes da Silva, A. I. E. Pintado, F. X. Malcata*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)
6 Downloads

Abstract

Production of lactan, a polysaccharide composed of mannose, galactose and galacturonic acid (at the ratio of 5:3:2), starting from a semidefined medium containing lactose via fermentation with Rahnella aquatilis was described previously. In this communication, such polysaccharide was produced from five alternative fermentation media: (1) a synthetic (defined) medium, plain whey (under (2) aerobic and (3) anaerobic conditions), (4) whey permeate and (5) whey with 2% NaCl (w/v). The effect of the concentration of polysaccharide, pH and ionic strength at harvest on the rheological properties of the polysaccharide was studied using lactan-enriched fractions recovered from each medium and analysed in solution under steady shear flow. Lactan solutions showed a shear-thinning behaviour in all cases, and increases in viscosity were observed at increasing concentrations of polysaccharide, as expected. The polysaccharide fraction produced from whey with 2% (w/v) NaCl and plain whey under anaerobic conditions exhibited lower viscosity than that produced from the other media, an observation that is associated with the lower concentration of polysaccharide. Post-harvest addition of salts (KCl or CaCl 2) and changes in pH (3–11) affected slightly the viscosity of the polysaccharide solutions.
Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalCarbohydrate Polymers
Volume37
Issue number1
DOIs
Publication statusPublished - Sept 1998

Keywords

  • Lactan
  • Rahnella aquatilis
  • Polysaccharide

Fingerprint

Dive into the research topics of 'Rheological characterization under shear of a fraction of polymer produced via fermentation of whey-related media by Rahnella aquatilis'. Together they form a unique fingerprint.

Cite this