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Characterizing maize starch gelatinization by Low-Field NMR spectroscopy
Li Ding1, Samira Ebrahimi2, Xingxun Liu3
1Copenhagen Plant Science Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Denmark.
Carbohydrate Polymers
|September 19, 2025
Summary
Low-field NMR reveals how water moves during starch swelling and gelatinization. Starch swelling involves water entering granules, while gelatinization releases water from them.
Area of Science:
- Food Science
- Biophysics
- Analytical Chemistry
Background:
- Starch swelling and gelatinization are critical processes in food science and biophysics.
- Understanding water dynamics within starch granules is key to controlling these transformations.
- Low-field nuclear magnetic resonance (LF-NMR) spectroscopy offers a non-invasive method to probe these dynamics.
Purpose of the Study:
- To investigate the role of different water populations in starch swelling and gelatinization using LF-NMR.
- To elucidate the mechanisms of water migration during starch thermal transitions.
- To correlate LF-NMR parameters with starch structure and thermal properties.
Main Methods:
- Analysis of transverse relaxation time (T2) of water protons in starch using LF-NMR spectroscopy.
- Monitoring changes in three distinct water proton populations (T21, T22, T23) and their relative concentrations (M21, M22, M23) during heating.
- Correlation analysis (Pearson) between LF-NMR data and starch structural/thermal properties (FTIR, gelatinization temperature).
Main Results:
- Starch swelling (40-60°C) involves water moving from extra-granular (T22) to intra-granular (T21) regions.
- Gelatinization (80°C) is characterized by water redistribution from intra-granular (T21) to extra-granular (T22) regions.
- Acetylation (AC) retards and prolongs swelling and gelatinization by altering water mobility.
Conclusions:
- LF-NMR effectively differentiates water populations involved in starch swelling and gelatinization.
- Water migration patterns provide insights into the distinct mechanisms of swelling and gelatinization.
- LF-NMR parameters correlate with starch structure and thermal behavior, offering potential for quality assessment.
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