Pectin Internal Gel Strength: Theory, Measurement, and Methodology

Crandall, Philip G.; Wicker, Louise

doi:10.1021/bk-1986-0310.ch008

Cited by 28 publications

(24 citation statements)

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“…With an increase in pectin concentration, the effect of water-pectin interaction increases, but this effect is linearly proportional to the pectin concentration. The pectin-pectin interaction, however, increases proportionally to the square of pectin concentration so that an increase in E a with an increase in pectin concentration should be attributed to the increase in the pectin-pectin interaction comprising hydrogen-bonding and hydrophobic interaction for highmethoxyl pectins (Oakenfull and Scott, 1984;Crandall and Wicker, 1986;Oakenfull, 1991). Oakenfull and Scott (1984) quantitatively evaluated the contributions of the hydrogenbonding and hydrophobic interactions to the pectin-pectin interaction in the gelation process of high-methoxyl pectin.…”

Section: Resultsmentioning

confidence: 99%

“…When methoxyl content is high, the solution properties of pectin are known to be strongly affected by the coexistence of sugars (Chen and Joslyn, 1967;Crandall and Wicker, 1986;Kar and Arslan, 1999a;Bulone et al, 2002;Fishman et al, 2004;Sato et al, 2004). However, the detailed mechanism of the effect of sugars has been not fully understood.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of Intermolecular Interaction among Pectin Molecules in Aqueous Sugar Solutions

Sato

Miyawaki

2008

FSTR

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Although the viscosity of aqueous solution of high methoxyl pectin is known to increase drastically when sugars coexist, the detailed mechanism for the increase in viscosity was not fully understood. Therefore, the viscosity of citrus and apple pectin solutions with various sugars compositions was measured with temperature varying from 5 to 40℃ to analyze the intermolecular interactions among pectin molecules. For single-composition pectin solutions, the activation energy for viscosity, E a , increased from 17.5 to 31.9 kJ/mol with an increase in pectin concentration up to 2% for the case of citrus pectin, reflecting the increase in pectin-pectin interaction. For pectin solutions with coexisting sugars, E a increased more with increasing sugar concentration. When compared at the same water activity, the increase in E a is also dependent on the type of sugar. Sugars with stronger solvent-ordering activity produced greater increases in E a . These results suggest that sugars increase the pectin-pectin interaction both through their own hydration effect, which enhances the hydrogen bonding among pectin molecules, and through the solventordering effect to enhance the hydrophobic interaction.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of Intermolecular Interaction among Pectin Molecules in Aqueous Sugar Solutions

Sato

Miyawaki

2008

FSTR

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“…Apoplastic changes in pH and ionic concentration may regulate softening by modifying activity of cell wall degrading enzymes (Almeida & Huber 1999). Also, pH interacts with the degree of esterification of pectin to affect the strength of pectin gels (Crandall & Wicker 1986). It is possible that changes in apoplastic pH and degree of pectin esterification affect the strength of pectin in apple, and thus softening.…”

Section: Apoplastic Phmentioning

confidence: 99%

Postharvest softening of apple (Malus domestica) fruit: A review

Johnston

Hewett²,

Hertog

2002

New Zealand Journal of Crop and Horticultural Science

198

136

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Postharvest softening of apple (Malus domestica (Borkh.)) fruit is a serious problem for growers in many countries, including New Zealand. To reduce this problem considerable research has been undertaken to determine the biological causes of softening so that this process can be managed or controlled more effectively. This review describes the pattern of softening for harvested apple fruit, and how it is influenced by different preharvest, atharvest, and postharvest factors. Information is also given on the likely physiological and biochemical causes of apple softening, such as fruit anatomy and cell packing, modification of the cell wall and membranes, changes in cell turgor, and the role of ethylene and other growth regulators. Despite many softening studies, there is still a poor understanding of what causes firmness variation in the marketplace. Until this understanding is improved, apple producers will continue to struggle to meet market requirements for texture.

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“…Rapid-set pectins with high DE will gel at higher pH than the one with lower degree esterifications; however, in slow-set pectin, this difference is minor, with the optimum pH for slow-set pectins being about 3.1 and for rapid-set pectins being 3.4 (Crandall and Wicker 1986). Low pH increases the percentage of unionized carboxyl groups, thus reducing electrostatic repulsion between adjacent pectin chains.…”

Section: Acidulantsmentioning

confidence: 99%