Physical aspects of the biopolymer matrix in wheat bran and its dissected layers

Hydration of Wheat Flour Water-Unextractable Cell Wall Material Enables Structural Analysis of Its Arabinoxylan by High-Resolution Solid-State 13C MAS NMR Spectroscopy

“…The authors reported an increase in spectral resolution upon sample hydration. Mense et al performed solid-state 1 H– 13 C CP MAS NMR to study wheat bran containing comparable AX and cellulose contents [each about 24% w/w of the dry matter (DM)]. Here, controlled hydration of the sample resulted in narrowing of the 13 C resonances, similar to what has been observed previously upon hydration of carbomers .…”

“…Enzymatic removal of starch and proteins from wheat bran further improved spectral resolution and reduced overlap between C -1 signals of glucose in cellulose and Xyl in AX. The reduced signal overlap was attributed to an increase in the effective concentration of AX and cellulose (about 43 and 28% w/w of DM, respectively) after removal of starch, protein, and water extractables …”

“…14,22 Although such procedures have allowed structural characterization through high performance size exclusion chromatography and liquid-state nuclear magnetic resonance (NMR) spectroscopy, they disrupt the native WU-AX structure by breaking covalent and non-covalent bonds. 23 Ha et al 24 have examined the polymers in destarched and defatted cell walls of wheat bran by solid-state 1 H− 25 Although solid-state 1 H− 13 C CP MAS NMR experiments have been performed on isolated AX or wheat cell wall material fractions, a full and detailed structural characterization of AX therein has in all cases been impaired by signal overlap and low spectral resolution. To the best of our knowledge, 13 C MAS NMR spectra with a resolution allowing structural analysis have not yet been obtained for the wheat flour unextractable cell wall material (UCWM).…”

“…We here reasoned that applying 13 C high-power decoupling (HPDEC) MAS NMR on partially hydrated samples could yield high resolution spectra and thus detailed structural characteristics which further can benefit studies of the role of WU-AX in flour processing and its impact on health. In what follows, we report the isolation of the wheat flour UCWM and, following limited hydration thereof, 25 analysis of its WU-AX by high-resolution 13 C HPDEC MAS NMR in a highly optimized environment.…”

Germinando semillas para la investigación. Una estrategia de futuro en Risaralda

“…Comparando los valores mencionados con el valor de 2.74±0.12 mg N/g para CP determinado en esta investigación, se tiene que el contenido de nitrógeno para la CP analizada está por debajo de lo esperado. En estudios previos se han realizado determinaciones de nitrógeno en salvado de trigo, reportando valores entre 15.84 mg N/g a 29.76 mg N/g y presencia de aminoácidos como acido glutámico, acido aspártico y alanina (Mao, Cone, Hendriks, & Sonnenberg, 2020) (Chaquilla, Balandrán, Medoza, & Mercado, 2017) (Mense, Zhang, Zhao, Liu, & Shi, 2020). La cantidad reportada de N para ST en este estudio es de 13.89±0.02 mg N/g lo que podría indicar que el salvado de trigo analizado posiblemente tenía déficit de nitrógeno.…”