The impact of chemical structure on polyphenol bioaccessibility, as a function of processing, cell wall material and pH: A model system

2021 ◽  
Vol 289 ◽  
pp. 110304 ◽  
Author(s):  
Eden Eran Nagar ◽  
Liora Berenshtein ◽  
Inbal Hanuka Katz ◽  
Uri Lesmes ◽  
Zoya Okun ◽  
...  
2017 ◽  
Vol 24 (6) ◽  
pp. 883-892 ◽  
Author(s):  
Jianjun Zhang ◽  
Zhihua Wang ◽  
Longmao Zhao

AbstractThe paper focuses on the effects of the cell wall material strain hardening on the mechanical behavior of closed-cell foams subjected to the constant velocity loading. Three-dimensional Voronoi models were established to present the closed-cell foams, and the simulations were performed by employing Ls-dyna 971. The investigation found that the cell wall strain hardening could postpone the onset of the localized collapse bands and retard deformation mode transformation. Strain hardening convergence phenomenon was observed in the closed-cell foams; increasing the impact velocity could weaken the effect of the material strain hardening. The crushing stress at both impact and stationary sides were analyzed in detail. The material strain hardening could always enhance the plastic energy dissipation. Furthermore, the strain hardening convergence was also observed in the plateau stress at the impact side and plastic energy dissipation but not in the densification strain and the plateau at the stationary side.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2110 ◽  
Author(s):  
Aude A. Watrelot ◽  
Erin L. Norton

Tannins are a group of polyphenols found in fruits, leaves, trees, etc., well known in the leather industry and in apples, persimmons and grapes, because of their capacity to interact with other polyphenols or other components either from the food product or from saliva. Prior to being able to interact with other compounds, tannins have to be extracted from the food matrix, which depends on their chemistry, as well as the chemical structure of other components, such as cell wall material and proteins. Vitis vinifera grapes are commonly grown around the world and are used in winemaking, providing good quality wines with different levels of tannins responsible for the final wine’s astringency. Many studies have focused on tannins extractability and retention with cell wall material, and the reactivity of tannins with proteins in Vitis vinifera grapes and wine, but there are very few reports for other Vitis species. However, depending on the environmental characteristics of certain regions, Vitis hybrid grapes are grown and used to produce wines more and more. This review focuses on the comparison of the chemistry of tannins, and their reactivity with other macromolecules in Vitis species.


2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin

Environmental contextSphagnum moss is a widespread species in peatlands globally and responsible for a large fraction of carbon storage in these systems. We used synchrotron infrared microspectroscopy to characterise the acid-base properties of Sphagnum moss and the conditions under which calcium uptake can occur (essential for plant tissue integrity). The work allows a chemical model for Sphagnum distribution in the landscape to be proposed. AbstractSphagnum is one the major moss types responsible for the deposition of organic soils in peatland systems. The cell walls of this moss have a high proportion of carboxylated polysaccharides (polygalacturonic acids), which act as ion exchangers and are likely to be important for the structural integrity of the cell walls. We used synchrotron light source infrared microspectroscopy to characterise the acid-base and calcium complexation properties of the cell walls of Sphagnum cristatum stems, using freshly sectioned tissue confined in a flowing liquid cell with both normal water and D2O media. The Fourier transform infrared spectra of acid and base forms are consistent with those expected for protonated and deprotonated aliphatic carboxylic acids (such as uronic acids). Spectral deconvolution shows that the dominant aliphatic carboxylic groups in this material behave as a monoprotic acid (pKa=4.97–6.04). The cell wall material shows a high affinity for calcium, with a binding constant (K) in the range 103.9–104.7 (1:1 complex). The chemical complexation model developed here allows for the prediction of the chemical environment (e.g. pH, ionic content) under which Ca2+ uptake can occur, and provides an improved understanding for the observed distribution of Sphagnum in the landscape.


1986 ◽  
Vol 62 (6) ◽  
pp. 1703-1712 ◽  
Author(s):  
H. G. Jung ◽  
K. P. Vogel

Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 344-347 ◽  
Author(s):  
Walter E. Splittstoesser

Barley (Hordeum vulgareL. var. Trail) root growth was inhibited at lower concentrations of 1-(2-methylcyclohexyl)-3-phenylurea (siduron) than was shoot growth. The influence of siduron upon root metabolism was assessed with excised roots grown in 0 or 5 ppm siduron. More glucose-U-14C and leucine-U-14C were degraded to CO2and less were incorporated into cell wall material and protein by roots grown in siduron. However, roots grown in siduron incorporated more adenine-8-14C into nucleic acids and degraded less adenine to CO2than roots grown in water. It was suggested that siduron disrupted the normal nucleic acid metabolism of barley roots which was necessary for protein and cell wall synthesis.


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