Methods for Analysis of Dietary Fibre

Selvendran, Robert R.; Verne, A. Verena F. V.; Faulks, Richard M.

doi:10.1007/978-3-642-83349-6_13

Cited by 12 publications

(13 citation statements)

References 54 publications

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“…After homogenisation the mixture was kept in a bath at 100°C for 1 h, taking care to maintain constant the total volume indicated and with mixing from time to time. [17][18][19] When the suspension was at room temperature, pectin 20 and methanol 21 determinations were performed. The degree of methylation was then calculated.…”

Section: Polygalacturonase (Pg) Activitymentioning

confidence: 99%

Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure

et al. 2003

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Textural, histological and biochemical characteristics of cucumber (Cucumis sativus L) under different tissue turgor pressures were studied after equilibration of mesocarp tissue cylinders in various polyethylene glycol 400 (PEG) solutions. Tissue swelling was observed for all hypotonic solutions. Cell membrane vitality was detected in all cucumber tissues where significant values of initial firmness (f i ) and residual relaxation force (F R ) were found. Good turgor status was also associated with higher values of these parameters, observing higher values of the textural parameters for higher turgor. Cell wall integrity was observed through Calcofluor fluorescence assay in tissue equilibrated in hypotonic, isotonic and hypertonic solutions, although a lower fluorescence intensity was observed in tissue equilibrated with 0 mol m À3 PEG solution, probably owing to some cell bursting. Calcium bridges between pectic polymers were proven to be responsible for cell-cell adhesion and tissue integrity of cucumber mesocarp tissue. Compression curves obtained for raw tissue showed a stage of fracture, and its loss after immersion might be attributed to cell-cell adhesion weakness due to immersion in calcium-free PEG solutions. Peroxidase and polygalacturonase increased after cucumber equilibration in the solutions, probably expressing tissue injury. Cucumber textural behaviour was very much affected by immersion in calcium-free solutions, determining the loss of fracture stage and a great influence of turgor pressure on the textural response of soaked tissue. INTRODUCTIONTexture is a major quality attribute of plant-based foods. This property lies in a 'mechanical unit' whose components are the cell wall, the cellular membrane or plasmalemma and the middle lamella. The cell wall and middle lamella work together, controlling the way in which vegetable tissues undergo mechanical deformation and failure during mastication. 1 The relative resistance of these two entities determines the perception of juiciness or mealiness, 2 but it is also affected by cell adhesion which can be attributed to various chemical compounds. These are key factors which determine the textural performance of vegetables after physiological changes such as ripening or after processes such as blanching, cooking or brining. Mechanical properties are also influenced by cell wall thickness, the size and shape of cells, the volume of intercellular spaces and turgor 3-5 as well as by the frequency of plasmodesmata presence along the cell wall and by the type of chemical compounds that constitute it.

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Section: Polygalacturonase (Pg) Activitymentioning

confidence: 99%

Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure

et al. 2003

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“…Fibres from vegetables have, in comparison to those from cereals, three main characteristics (Selvendran et al 1989;Thibault et al 1992):…”

Section: Discussionmentioning

confidence: 99%

“…Another disadvantage of AIS is that boiling ethanol and severe drying may change some physicochemical properties (solubility, porosity, etc.) These conditions have been discussed in detail by Selvendran et al (1989), who suggested to decrease the temperature of the 'prehydrolysis' to 20 0 e and to increase the reaction time to 2-3 h in order to minimize losses, especially in arabiQose and rhamnose. An alternative is to isolate the cell walls using aqueous, inorganic solvents instead of ethanol.…”

Section: Preparation Of Fibre For Its Characterizationmentioning

confidence: 99%

Vegetables and Vegetable Products

1994

Modern Methods of Plant Analysis

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“…The AIR was homogenized, dried overnight and hydrolysed using the method of Selvendran et al (1989). Two aliquots of 20 mg AIR of each sample were resuspended in 1 ml of 12 M H 2 SO 4 and incubated for 2 h at room temperature.…”

Section: Manipulation Of Dnamentioning

confidence: 99%

Expression of a Petunia inflata pectin methyl esterase in Solanum tuberosum L. enhances stem elongation and modifies cation distribution

Pilling

Willmitzer

Fisahn

2000

Planta

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Transgenic potato (Solanum tuberosum L.) plants were constructed with a Petunia in¯ata-derived cDNA encoding a pectin methyl esterase (PME; EC 3.1.1.11) in sense orientation under the control of the cauli¯ower mosaic virus 35S promoter. The PME activity was elevated in leaves and tubers of the transgenic lines but slightly reduced in apical segments of stems from mature plants. Stem segments from the base of juvenile PME-overexpressing plants did not dier in PME activity from the control, whereas in apical parts PME was less active than in the wild-type. During the early stages of development stems of these trangenic plants elongated more rapidly than those of the wild-type. Further evidence that overexpression of a plant-derived PME has an impact on plant development is based on modi®cations of tuber yield, which was reduced in the transgenic lines. Cell walls from transgenic tubers showed signi®cant dierences in their cation-binding properties in comparison with the wildtype. In particular, cell walls displayed increased anity for sodium and calcium, while potassium binding was constant. Furthermore, the total ion content of transgenic potatoes was modi®ed. Indications of PMEmediated dierences in the distribution of ions in transgenic plants were also obtained by monitoring relaxations of the membrane potential of roots subsequent to changes in the ionic composition of the bathing solution. However, no eects on the chemical structure of pectin from tuber cell walls could be detected.

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Methods for Analysis of Dietary Fibre

Cited by 12 publications

References 54 publications

Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure

Textural, histological and biochemical changes in cucumber (Cucumis sativus L) due to immersion and variations in turgor pressure

Vegetables and Vegetable Products

Expression of a Petunia inflata pectin methyl esterase in Solanum tuberosum L. enhances stem elongation and modifies cation distribution

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