# Correlation of T2 NMR with Tg/T and viscosity

## TL;DR

This paper shows that T2 NMR relaxation times correlate with Tg/T and viscosity in carbohydrates, offering a new way to screen sugar replacers.

## Contribution

The study establishes a direct correlation between T2 NMR relaxation times and the Tg/T ratio, linking it to viscosity and plasticizing behavior.

## Key findings

- T2 relaxation times of small carbohydrates collapse onto a universal master curve with Tg/T.
- T2 NMR accurately estimates the glass transition temperature of carbohydrates with 1%-2% deviation.
- T2 NMR is a promising high-throughput method for evaluating novel sugar replacers.

## Abstract

Using both literature and new experimental data, we demonstrate that T2 relaxation times are governed by the ratio Tg/T, where Tg is the moisture-dependent glass transition temperature and T is the actual temperature. This ratio, Tg/T, is known to control the viscosity and plasticizing behavior of small carbohydrates, as well as the rheological properties of biopolymeric systems such as starch and plant proteins. For small carbohydrates, the T2 data collapse onto a universal master curve, analogous to their viscosity behavior. For biopolymers, however, the current dataset is insufficient to confirm the existence of such a master curve. Additionally, we show that T2 NMR provides an accurate estimate of the glass transition temperature of small carbohydrates, with deviations within 1%–2%. This makes it a promising method for high-throughput screening of the plasticizing properties of novel sugar replacers.

Graphical abstract Image 1

•Logarithmic T2 relaxation time scales of carbohydrates with Tg/T.•Logarithmic T2 relaxation time scales of carbohydrates with viscosity.•T2 NMR method is an accurate method for determining glass transition.•T2 NMR is a promising high-throughput method for screening novel sugar replacers.

Logarithmic T2 relaxation time scales of carbohydrates with Tg/T.

Logarithmic T2 relaxation time scales of carbohydrates with viscosity.

T2 NMR method is an accurate method for determining glass transition.

T2 NMR is a promising high-throughput method for screening novel sugar replacers.