Study on water proton distribution and flow status of starch during the hydration process

The use of time domain 1H NMR to study proton dynamics in starch‐rich foods: A review

“…They attributed this increased starch proton mobility to the plasticizing effects of water on starch. A similar effect was observed for rice and potato starches, which displayed a rise in T 2 relaxation time from nonexchanging protons of crystalline and amorphous starch from 9 to 13 μs and 14 μs, as moisture increased from 20% to 90%, respectively (Wu et al, 2018).…”

“…The extragranular water proton fraction has frequently been characterized as a separate fraction from the intragranular water in potato (Reyniers, Vluymans, et al., 2020; Tang et al., 2000), maize (Tang et al., 2000), wheat (Bosmans et al., 2012; Kovrlija & Rondeau‐Mouro, 2017b), and pea (Tang et al., 2000) starch. However, experiments on rice starch (type A form) uncovered only one broad CPMG population ( T 2 relaxation time of 0.27–3.28 ms) at moisture contents between 20% and 90% (Wu et al., 2018). This proton population was determined to represent nonexchanging protons of amorphous starch, exchanging protons from starch and intragranular water, and extragranular water protons.…”

“…This proton population was determined to represent nonexchanging protons of amorphous starch, exchanging protons from starch and intragranular water, and extragranular water protons. Rice starch granules are small in size (Delcour & Hoseney, 2010) and thus would indeed experience faster diffusive/chemical exchange (Wu et al., 2018). Authors proposed that this potentially contributed to the inability to distinguish between separate proton populations.…”

“…T 2 relaxation times are positively related to molecular mobility (Leung et al., 1979; Schmidt, 2020). Additionally, T 2 relaxation closely reflects molecular and structural changes occurring during starch hydrothermal treatments such as starch swelling and/or gelatinization (Lelievre & Mitchell, 1975; Wu et al., 2018). For this reason, examination of T 2 relaxation behavior is the focus of this article.…”

Effect of Hydrophobic Hydration on the Self-Assembling Behavior of Poly (l-Lactide) Homopolymers with an Ionic End Group

“…The discussion of hydrophobic hydration of PLLA­[PPh 2 Me]I is further supported by low-field nuclear magnetic resonance (LF-NMR) relaxometry analysis . As shown in Figure a, the two relaxation time signals ( T 2 ) related to water motions at 0.1–10 and 100–1000 ms are assigned to the strongly ( T 2 S ) and weakly ( T 2 W ) bound water, respectively, ,− and so the dependence of these two signals on the solution conditions helped us to further understand the hydrophobic hydration and dehydration of the macromolecules. T 2 S is attributed to the relaxation time for the water bound to the backbone, whose intensity is high at a water content of 33.3% and becomes too weak to be detected at a water content of 60.0%.…”