Main content area

Unique hydration behavior of potato starch as determined by deuterium nuclear magnetic resonance

Yakubu, P.I., Baianu, I.C., Orr, P.H.
Journal of food science 1990 v.55 no.2 pp. 458-461
potato starch, physicochemical properties, deuterium, nuclear magnetic resonance spectroscopy
Deuterium Nuclear Magentic Resonance (NMR) measurements at 4.7 Tesla revealed a unique hydration behavior of potato starch that involved the presence of a tightly bound water population with anisotropic motions within the potato starch granule, even in the presence of excess, bulk water in potato starch slurries. Well-defined powder patterns with residual deuterium quadrupole splittings of about 1 kHz were also observed at 20 degrees C for raw potato tubers. Three other water populations, a weakly bound, a surface-trapped, and a bulk water population, were also present up to 60% starch and were in fast exchange with each other at room temperature, resulting in a broadened, single Lorentzian 2H NMR peak. These three water populations were absent below 35% moisture content in potato starch, but not in corn starch. The unique hydration properties of potato starch might be important for novel processing methodology.