TY - JOUR
T1 - Apparent yield stress estimation in xanthan gum solutions and fermentation broths using a low-cost viscometer
AU - Hannote, M.
AU - Flores, F.
AU - Torres, L.
AU - Galindo, E.
N1 - Funding Information:
This work was financed in part by D-GAPA/ UNAM (grant IN-3025.89). M.H. received support from the French Government as V.S.N.A. We thank Spectrum S~A. for providing the samples of xanthan gum. We are grateful to A. Martinez for his assistance with the power techniques and cavern measurements and to G. Araiza for her help in yield stress determinations. We thank E. Brito for providing the software for rheological estimations and for revision of the preliminary manuscript. We also thank A. Garcia-Rejdn and the referees for their very helpful comments.
PY - 1991
Y1 - 1991
N2 - The apparent yield stress, a rheological property important in determining the extent of mixing in xanthan fermentations as well as the suspending ability of the gum solutions, was determined for xanthan solutions (10-50 g l-1) and fermentation broths containing 12-30 g l-1 of xanthan, by model fitting and stress relaxation methods. By using a low-cost viscometer, a rapid relaxation technique proved to be reliable and preferable to the fitting of theoretical models. The yield stress increased with xanthan concentration, but different behaviour was observed for different xanthan sources and salt concentrations. Different apparent yield stresses were measured for fermentation broths and solutions of commercial xanthans of identical concentration. Apparent yield stress values were used successfully for the prediction of the size of the well mixed region in xanthan and Carbopol solutions in a stirred tank.
AB - The apparent yield stress, a rheological property important in determining the extent of mixing in xanthan fermentations as well as the suspending ability of the gum solutions, was determined for xanthan solutions (10-50 g l-1) and fermentation broths containing 12-30 g l-1 of xanthan, by model fitting and stress relaxation methods. By using a low-cost viscometer, a rapid relaxation technique proved to be reliable and preferable to the fitting of theoretical models. The yield stress increased with xanthan concentration, but different behaviour was observed for different xanthan sources and salt concentrations. Different apparent yield stresses were measured for fermentation broths and solutions of commercial xanthans of identical concentration. Apparent yield stress values were used successfully for the prediction of the size of the well mixed region in xanthan and Carbopol solutions in a stirred tank.
UR - http://www.scopus.com/inward/record.url?scp=0026103288&partnerID=8YFLogxK
U2 - 10.1016/0300-9467(91)80018-R
DO - 10.1016/0300-9467(91)80018-R
M3 - Artículo
SN - 0300-9467
VL - 45
SP - B49-B56
JO - The Chemical Engineering Journal
JF - The Chemical Engineering Journal
IS - 3
ER -