TY - JOUR
T1 - Instrumental characterization of xanthan gum and scleroglucan solutions
T2 - comparison of rotational rheometry, capillary breakup extensional rheometry and soft-contact tribology
AU - Li, Xinxin
AU - Harding, Stephen E.
AU - Wolf, Bettina
AU - Yakubov, Gleb
PY - 2022/9
Y1 - 2022/9
N2 - Xanthan gum and scleroglucan, two rod-like polysaccharide hydrocolloids, are compared using a wide range of instrumental techniques and methods: steady shear flow, small amplitude oscillatory shear, first normal stress difference, capillary break-up and soft-contact tribology. The aqueous solutions of these two hydrocolloids with similar flow and viscoelastic profile show marked differences in capillary break-up time and apparent extensional viscosity. This result correlates with differences in first normal stress difference and, to a lesser extent, Stribeck curve behaviour. Formulating the hydrocolloids in concentrated sucrose solution (40 wt%) shifts relaxation profiles to longer times which greatly diminishes differences in rheological and lubrication behaviour. With exception of capillary break-up tests, no other methods showed statistically significant differences between the polysaccharides dissolved in the viscosified matrix. The toolbox of techniques is also applied to probe interactions of xanthan gum and scleroglucan with human whole saliva and bovine submaxillary mucin. We report no specific interactions between either hydrocolloid and salivary proteins and suggest that any cumulative effects must stem from specific sets of linear and non-linear rheological properties of saliva/hydrocolloid mixtures.
AB - Xanthan gum and scleroglucan, two rod-like polysaccharide hydrocolloids, are compared using a wide range of instrumental techniques and methods: steady shear flow, small amplitude oscillatory shear, first normal stress difference, capillary break-up and soft-contact tribology. The aqueous solutions of these two hydrocolloids with similar flow and viscoelastic profile show marked differences in capillary break-up time and apparent extensional viscosity. This result correlates with differences in first normal stress difference and, to a lesser extent, Stribeck curve behaviour. Formulating the hydrocolloids in concentrated sucrose solution (40 wt%) shifts relaxation profiles to longer times which greatly diminishes differences in rheological and lubrication behaviour. With exception of capillary break-up tests, no other methods showed statistically significant differences between the polysaccharides dissolved in the viscosified matrix. The toolbox of techniques is also applied to probe interactions of xanthan gum and scleroglucan with human whole saliva and bovine submaxillary mucin. We report no specific interactions between either hydrocolloid and salivary proteins and suggest that any cumulative effects must stem from specific sets of linear and non-linear rheological properties of saliva/hydrocolloid mixtures.
KW - Bovine submaxillary mucin
KW - Capillary break-up
KW - First normal stress difference
KW - Rheology
KW - Saliva
KW - Scleroglucan
KW - Small amplitude oscillatory shear
KW - Soft-contact tribology
KW - Xanthan gum
UR - http://www.scopus.com/inward/record.url?scp=85128846895&partnerID=8YFLogxK
U2 - 10.1016/j.foodhyd.2022.107681
DO - 10.1016/j.foodhyd.2022.107681
M3 - Letter
SN - 0268-005X
VL - 130
JO - Food Hydrocolloids
JF - Food Hydrocolloids
M1 - 107681
ER -