Chemically methylated and reduced pectins: preparation, characterisation by 1H NMR spectroscopy, enzymatic degradation, and gelling properties

Rosenbohm, Christoph; Lundt, Inge; Christensen, Tove; Young, Niall W. G.

doi:10.1016/s0008-6215(02)00440-8

Cited by 133 publications

(67 citation statements)

References 35 publications

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“…DM was determined by integrating the spectral regions of H5 for the nonmethylesterified and methylesterified peaks that were fully resolved, as opposed to the other resonances. The assignments correspond to proton resonances previously reported (Grasdalen et al, 1988;Rosenbohm et al, 2003). Corresponding 13 C resonances were identified by recording two-dimensional 1 H-13 C spectra of 95% methyl-esterified citrus pectin and poly GalUA (both from Sigma-Aldrich).…”

Section: Nmrsupporting

confidence: 58%

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

et al. 2007

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Wood cells, unlike most other cells in plants, grow by a unique combination of intrusive and symplastic growth. Fibers grow in diameter by diffuse symplastic growth, but they elongate solely by intrusive apical growth penetrating the pectin-rich middle lamella that cements neighboring cells together. In contrast, vessel elements grow in diameter by a combination of intrusive and symplastic growth. We demonstrate that an abundant pectin methyl esterase (PME; EC 3.1.1.11) from wood-forming tissues of hybrid aspen (Populus tremula 3 tremuloides) acts as a negative regulator of both symplastic and intrusive growth of developing wood cells. When PttPME1 expression was up-and down-regulated in transgenic aspen trees, the PME activity in wood-forming tissues was correspondingly altered. PME removes methyl ester groups from homogalacturonan (HG) and transgenic trees had modified HG methylesterification patterns, as demonstrated by two-dimensional nuclear magnetic resonance and immunostaining using PAM1 and LM7 antibodies. In situ distributions of PAM1 and LM7 epitopes revealed changes in pectin methylesterification in transgenic trees that were specifically localized in expanding wood cells. The results show that en block deesterification of HG by PttPME1 inhibits both symplastic growth and intrusive growth. PttPME1 is therefore involved in mechanisms determining fiber width and length in the wood of aspen trees.

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Section: Nmrsupporting

confidence: 58%

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

et al. 2007

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“…The total sugar content of the polysaccharide fractions was between 74.4% and 86.2%, similar to values the levels found for polysaccharides extracted from fruits of Cambridge shire [19]. The physico-chemical properties of polysaccharides are determined by monosaccharide composition and content of uronic acids [20]. The highest proportion of uronic acid was detected in a fraction extracted with citric acid 0.5%/ 50°C/60 min in less drastic conditions ( Table 5).…”

Section: Chemical Characterization Of Polysaccharides Extracted Fromsupporting

confidence: 80%

Evaluation of the Technological Potential of Gabiroba [Campomanesia xanthocarpa Berg] Fruit

Ms¹,

Ch²,

Clo³

et al. 2012

J Nutr Food Sci

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Native fruits are receiving special attention from food researchers all around the world. The Campomanesia xanthocarpa Berg [gabirobeira] is a species native to Brazil, being part of family Myrtaceae. The gabirobeira produces a fruit named gabiroba, whose pulp presents a nice acidic-sweet taste. This work was aimed at evaluating the gabiroba technological potential for use as a raw material for the food industry. The gabiroba pulp was evaluated for its physical-chemical features. In addition, the pectin that was extracted from the pulp was evaluated for its rheological features. The pulp bioactive compounds content, namely vitamin C, flavonoids, phenolics and carotenoids, was measured during 180 days of freezer storage. The pulp antioxidant capacity was measured by means of the DPPH and ABTS methods. The rheological measurements were performed through the use of a Haake RS 75 rheometer. The generated flow curves were fitted by means of the Power Law and Herschel-Bulkley models. Results show that the gabiroba contains remarkable contents of iron, phosphorus, zinc, manganese, total phenolics [131.90 mg/100 g, expressed as galic acid], vitamin C [312.21 mg/100 g] and total carotenoids [290.84 μg/g]. About 42% of the carotenoids corresponded to beta-carotene. During pulp storage, it was observed a decrease of 10.00% in total phenolics content, 5.35% in flavonoids and 23.52% in the vitamin C. There was a positive and significant correlation between antioxidant capacity and bioactive compounds content, suggesting that such capacity might be influenced in a synergic way by the detected bioactive compounds. The gabiroba pulp pectin presented a shearthinning behavior, being the data best fitted by the Herschel-Bulkley model. The viscoelastic measurements showed that the dynamic moduli are frequency independent. Concluding, gabiroba showed a remarkable potential to be used as a raw material in the food industry due to its rheological, functional [phytochemicals], sensory and nutritional [vitamins and mineral salts] features. Despite their large fructification, in addition to nutritional and attractive sensory characteristics, these fruits are not collected, being lost in the fields. In this work, the fruit pulp without seed [1500 g] was crushed in ethanol/water at a ratio of 1:4 [v/v], refluxed for 15 minutes at boiling temperature. The residue obtained was subjected to sequential extractions. The extractions were optimized using a factorial design 2 2 , with the concentration of citric acid [0.5 and 5%] and temperature [50 and 100ºC] as variables. The polysaccharides were characterized according to their chemical composition and rheological profile. The high concentrations of uronic acids, arabinose and galactose, detected in all fractions, indicate that they consist of pectin. The results showed that the extraction method was efficient for fractionation of pectin from different areas of the cell wall. The polysaccharides extracted from the fruit pulp of gabiroba showed a pseudoplastic behavior. All the fractions...

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“…A wide range of different methods have been applied to study both the dynamic and structural aspects of these gelation processes. Calcium induced gelation of LM pectins have been already studied by rheological methods [3,[7][8][9][10][11][12][13], circular dichroism [4], NMR [2,[14][15][16][17][18], dynamic light scattering (DLS) [19], and molecular modelling methods [5]. The results of the studies have confirmed a strong binding of calcium to pectin molecules and suggested a two-stage process of the ionic LM pectin gelation, in which the formation of strongly linked dimmer associations is followed by the appearance of weak inter-dimmer associations, mainly governed by electrostatic interactions.…”

Section: Introductionmentioning

confidence: 99%

¹H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions

2005

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The 1 H NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheometry have been applied to study the ionic gelation of 1% w/w aqueous low methoxyl pectin solution induced by divalent Ca 2+ cations from a calcium chloride solution. The model-free approach to the analysis of 1 H NMR relaxometry data has been used to separate the information on the static (β) and dynamic ( τc ) behaviour of the systems tested. The 1 H NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (β, τ c and T2 vs. CaCl2 concentration) is consistent with the two-stage gelation process of low methoxyl pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl 2 ) is followed by the appearance of weak inter-dimer aggregations (for CaCl2 ≥ 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl 2 has been confirmed by rheological measurements. Apart from that, the T1 and T2 relaxation times have been found to be highly sensitive to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability.

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Chemically methylated and reduced pectins: preparation, characterisation by 1H NMR spectroscopy, enzymatic degradation, and gelling properties

Cited by 133 publications

References 35 publications

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Evaluation of the Technological Potential of Gabiroba [Campomanesia xanthocarpa Berg] Fruit

¹H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions

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Chemically methylated and reduced pectins: preparation, characterisation by 1H NMR spectroscopy, enzymatic degradation, and gelling properties

Cited by 133 publications

References 35 publications

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Evaluation of the Technological Potential of Gabiroba [Campomanesia xanthocarpa Berg] Fruit

1H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions

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¹H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions