TY - JOUR
T1 - A new NMR method for directly monitoring and quantifying the dissolution kinetics of starch in DMSO
AU - Dona, Anthony C.
AU - Yuen, Chun-Wai Wayne
AU - Peate, Jonathan
AU - Gilbert, Robert G.
AU - Castignolles, Patrice
AU - Gaborieau, Marianne
PY - 2007
Y1 - 2007
N2 - The kinetics of dissolution of starch is needed for (i) understanding digestive processes; (ii) providing data that could correlate with higher levels of starch structure; (iii) improving techniques for starch characterization in solution. A novel method is presented here to directly monitor these dissolution kinetics by time-resolved 1H solution-state nuclear magnetic resonance (NMR); studies were carried out in deuterated dimethyl sulfoxide (DMSO-d6). By assuming pseudo-first-order kinetics with respect to starch concentration, the data for various starch samples yield values of the apparent rate coefficients for the rate of appearance of completely dissolved anhydroglucose units, results which have not been obtained hitherto. The presence of a limited amount of water in DMSO had a drastic effect on dissolution kinetics (slowing it down at high temperatures), indicating multiple pathways for the dissolution mechanism. Dynamic light scattering (DLS) appears to be more limited than the NMR method to monitor the kinetics of dissolution. The newly developed NMR method can be extended to other solvents and polysaccharides.
AB - The kinetics of dissolution of starch is needed for (i) understanding digestive processes; (ii) providing data that could correlate with higher levels of starch structure; (iii) improving techniques for starch characterization in solution. A novel method is presented here to directly monitor these dissolution kinetics by time-resolved 1H solution-state nuclear magnetic resonance (NMR); studies were carried out in deuterated dimethyl sulfoxide (DMSO-d6). By assuming pseudo-first-order kinetics with respect to starch concentration, the data for various starch samples yield values of the apparent rate coefficients for the rate of appearance of completely dissolved anhydroglucose units, results which have not been obtained hitherto. The presence of a limited amount of water in DMSO had a drastic effect on dissolution kinetics (slowing it down at high temperatures), indicating multiple pathways for the dissolution mechanism. Dynamic light scattering (DLS) appears to be more limited than the NMR method to monitor the kinetics of dissolution. The newly developed NMR method can be extended to other solvents and polysaccharides.
KW - dimethyl sulfoxide
KW - nuclear magnetic resonance
UR - http://handle.uws.edu.au:8081/1959.7/505083
M3 - Article
SN - 0008-6215
VL - 342
SP - 2604
EP - 2610
JO - Carbohydrate Research
JF - Carbohydrate Research
IS - 17
ER -