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

Abstract

Starch is a major contributor to the carbohydrate portion of our diet. When it is present with water, it undergoes several transformations during heating and/or cooling making it an essential structure-forming component in starch-rich food systems (e.g., bread and cake). Time domain proton nuclear magnetic resonance (TD 1 H NMR) is a useful technique to study starch-water interactions by evaluation of molecular mobility and water distribution. The data obtained correspond to changes in starch structure and the state of water during or resulting from processing. When this technique was first applied to starch(-rich) foods, significant challenges were encountered during data interpretation of complex food systems (e.g., cake or biscuit) due to the presence of multiple constituents (proteins, carbohydrates, lipids, etc.). This article discusses the principles of TD 1 H NMR and the tools applied that improved characterization and interpretation of TD NMR data. More in particular, the major differences in proton distribution of various dough and cooked/baked food systems are examined. The application of variabletemperature TD 1 H NMR is also discussed as it demonstrates exceptional ability to elucidate the molecular dynamics of starch transitions (e.g., gelatinization, gelation) in dough/batter systems during heating/cooling. In conclusion, TD NMR is considered a valuable tool to understand the behavior of starch and water that relate to the characteristics and/or quality of starchy food products. Such insights are crucial for food product optimization and development in response to the needs of the food industry.

Effect of water content on gelatinization functionality of flour from sprouted sorghum

“…Moving from 56% to 73% water, the mobility of Pop EF increased with increasing water content. Interestingly, for water contents ≥82%, a new separation of Pop EF occurred, allowing the distinction of Pop E and Pop F. According to Ruan et al (1999) , when all water-binding sites in the flour are saturated, further addition of water forms new, more mobile water layers with increasing distance to water molecules bound to the flour solids ( Ruan et al, 1999 ; Riley et al, 2022 ). Pop F would then show a progressive increase given the increase in water content, becoming the main population at water contents of 82 and 91%.…”

Non-Traditional Starches, Their Properties, and Applications

“…Time domain 1 H NMR can evaluate the molecular mobility and water distribution in the starch-water systems [143]. This method can be applied to elucidate the molecular dynamics of starch transitions during gelatinization in dough/batter systems during heating/cooling and used in the quality control of starchy food products.…”

Liquid Nuclear Magnetic Resonance (NMR) Spectroscopy in Transition—From Structure Elucidation to Multi-Analysis Method

“…NMR is utilized in food surveillance and quality control and several articles have highlighted the potential of this technique before [11][12][13][14]. Additionally, 2 H NMR spectroscopysite-specific natural isotope fractionation (SNIF) as another NMR technique-has been proven to be an effective tool in wine analytics, regarding geographical origin, since the 1990s [15].…”