Residue Specific Hydration of Primary Cell Wall Potato Pectin Identified by Solid-State ¹³C Single-Pulse MAS and CP/MAS NMR Spectroscopy

Abstract

Hydration of rhamnogalacturonan-I (RG-I) derived from potato cell wall was analyzed by (13)C single-pulse (SP) magic-angle-spinning (MAS) and (13)C cross-polarization (CP) MAS nuclear magnetic resonance (NMR) and supported by (2)H SP/MAS NMR experiments. The study shows that the arabinan side chains hydrate more readily than the galactan side chains and suggests that the overall hydration properties can be controlled by modifying the ratio of these side chains. Enzymatic modification of native (NA) RG-I provided samples with reduced content of arabinan (sample DA), galactan (sample DG), or both side chains (sample DB). Results of these samples suggested that hydration properties were determined by the length and character of the side chains. NA and DA exhibited similar hydration characteristics, whereas DG and DB were difficult to hydrate because of the less hydrophilic properties of the rhamnose-galacturonic acid (Rha-GalA) backbone in RG-I. Potential food ingredient uses of RG-I by tailoring of its structure are discussed.

Heterogeneous distribution of pectin and hemicellulose epitopes in the phloem of four hardwood species

“…Together with the qualitative difference between the two cells as outlined above, these results indicate that the chemistry of SEs and CCs is differently regulated during cell development, since both cells are derived from the same cambial mother cell and undergo their own developmental process after unequal cell division from the cambial mother cell (Lalonde et al 2001;van Bel 2003). It is proposed that the ratio of galactan and arabinan side chains in RG-I and the degree of methyl-esterification can affect the cell wall porosity/hydration and thus the movement of fluid (Bidhendi and Geitmann 2016;Larsen et al 2011;Ulvskov et al 2005;Willats et al 2001). This may suggest that difference in the chemical structure of pectins between the two cell types may be related to the difference in the biological function between SEs (long-distance transport) and CCs (life maintenance of SEs).…”

“…The notable difference in side chains of RG-I between SEs (richer in arabinans) and parenchyma cells (richer in galactans) in all hardwood species studied (Table 1) may also reflect the relationship between the chemistry of cell walls and physiological function of cells. For example, arabinan side chains hydrate more readily than galactan side chains in potato RG-I (Bidhendi and Geitmann 2016;Larsen et al 2011). Several notable differences between CCs and parenchyma cells were also detected in the same hardwood species in relation with LM5/LM6, LM20, and LM15 epitopes, even though both cell types showed qualitatively similar distributional patterns of pectin and hemicellulose epitopes (i.e., presence of RG-I/HG/xyloglucan epitopes and absence of heteroxylan/ heteromannan epitopes) ( Table 1).…”

Tissue-specific rhamnogalacturonan I forms the gel with hyperelastic properties

“…Moreover, the increase in the binding force of water is associated with the increase in elastic modulus and decrease in Poisson's ratio of the gel formed by rhamnogalacturonan I. It is known that rhamnogalacturonans I with galactan side chains have higher water retaining capacity than those with arabinan ones [46,47]. The presence of strongly bound water in the sample of flax fiber cell wall rhamno galacturonan I could contribute to the formation of local ly ordered zones between polysaccharide galactan chains involved in gel formation.…”

Contribution of cell wall modifying enzymes on the texture of fleshy fruits: The example of apple

“…3). 28 On the other hand, it was shown that pectin side chains are able to link cellulose microfibrills. Other minor galacturonans can be distinguished as, for example, rhamnogalacturonan II (RG-II) and xylogalacturonan (XGA), the latter being particularly present in apple pectin.…”