## 2 Materials and Methods
### Bread Properties Analyses  
2.5.1. Specific Volume  
The specific volume of gluten-free bread was determined by the rapeseed displacement method, according to the AACC 10-05 International Approved Methods [31], and calculated in mL/g of bread.  
2.5.2. Texture Analysis  
The texture profile analysis of bread was performed with a TA.XTplus texture analyzer (Stable Micro System Co., Ltd., Surrey, UK) equipped with a 5 kg load cell [30]. Each sample was compressed twice with a cylindrical plunger probe with a diameter of 35 mm. The test parameters were as follows: 10.0 mm/s pre-test speed, 5.0 mm/s test speed, 5.0 mm/s post-test speed, and 40% strain. Bread loaves were cut into slices (25 mm thick each and the ends were discarded) and used to evaluate hardness, springiness, cohesiveness, chewiness, and resilience.  
2.5.3. Water Activity  
Measurements of water activity and transpiration rates were performed with a water diffusion and activity analyzer 'ADA-7' (COBRABID, Poznan, Poland) according to the method described in detail previously [32].  
2.5.4. Low Field Nuclear Magnetic Resonance (LF NMR) Relaxometry  
Measurements of spin-lattice (\(T_{1}\)) and spin-spin (\(T_{2}\)) relaxation times were performed using a pulse NMR spectrometer PS15T, operating at 15 MHz under a system-controlled temperature (Ellab, Poznan, Poland) in accordance with the method described by [PERSON] et al. [33]. The inversion-recovery pulse sequence was applied for measurements of \(T_{1}\) relaxation times [34]. Distances between RF pulses (\(t\)) were changed within the range from 20 to 80 ms and the repetition time was from 10 s. Each time, 32 FID signals and 119 points from each FID signal were collected. Calculations of the spin-lattice relaxation time values were performed with the assistance of the CracSpin program. The program for calculating relaxation parameters from experimental data uses the'spin grouping' approach. [PERSON]'s minimization method has been applied for fitting multiexponential decays. Time changes of the current value of the FID signal amplitude in the used frequency of impulses are described by the following formula:  
\[M_{z}(t)=M_{0}\bigg{\{}1-2\exp\bigg{(}\frac{-t}{T_{1}}\bigg{)}\bigg{\}}\]  
where \(M_{z}(t)\) is the actual magnetization value and \(M_{0}\) is the equilibrium magnetization value.  
Measurements of spin-spin (\(T_{2}\)) relaxation times were taken using the pulse train of the Carr-Purcell-Meiboom-Gill spin echoes (\(90-\tau/2-(180)_{n}\)) [34]. The distance (\(\tau\)) between 180 RF pulses ranged from 0.5 to 0.9 ms. The repetition time was 10 s. The number of spin echoes (\(n\)) was 100. Five accumulation signals were used.  
To calculate the spin-spin relaxation time values, the authors applied the adjustment of the echo amplitudes to the formula [35]:  
\[M_{x,y}\left(t\right)=M_{0}\sum_{i=1}^{n}\ p_{i}\exp\left[\frac{-t}{T_{2i}}\right]\]  
where \(M_{x,y}\left(t\right)\) is the echo amplitude, \(M_{0}\) is the equilibrium amplitude, and \(p_{i}\) is the fraction of protons relaxing with the spin-spin time \(T_{2i}\).  
Mean correlation times (\(\tau_{\text{c}}\)) were calculated used the method described by [PERSON] et al. [36].  
The calculations were performed by using the dedicated software using a nonlinear least-squares algorithm. The accuracy of the relaxation parameters has been estimated with the standard deviation. The presence of two proton fractions was determined for all analyzed systems.