Crosslinking statistics, 2. Relative reactivities of amylose hydroxyl groups

Luby, P.; Kuniak, Ľ.

doi:10.1002/macp.1979.021800916

Cited by 13 publications

(2 citation statements)

References 18 publications

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“…Our results on legume starches seem to follow the above trend, namely, that crosslinked native or gelatinized starches exhibit only slightly lower rates of hydrolysis than their unmodified counterparts. Cross linking of amylose by epichlorohydrin in aqueous alkaline solution has shown that the reactivity of a C-2 hydroxyl group was much greater than that of either C3 or C6 hydroxyl groups [32]. If such reactivity is also shown during cross linking with phosphorus oxychloride, then the reduced rates of hydro- Table 5 illustrates the pasting properties of native and crosslinked starches obtained with the Brabender ViscolAmylo- Table 5.…”

Section: Digestibility By A-amylasementioning

confidence: 99%

Effect of Cross‐Linking on Functional Properties of Legume Starches

1986

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Refined starches from lentil, fababean and field pea contained 38.5, 32.0 and 34.2% amylose, respectively, where the water binding capacities, swelling powers, susceptibilities to amylase digestibility and amylograph viscosities were in the order: lentil > fababean > field pea. This evidence and the X‐ray diffraction data suggested that the degrees of molecular association between starch chains, especially amylopectin, followed the order: field pea > fababean > lentil. Cross linking with phosphorus oxychloride decreased water binding capacity, swelling power, α‐amylase digestibility and 95°C viscosity in the amylograph but increased the degree of set‐back. X‐ray diffraction patterns indicated that cross linking occurred mainly in the amorphous regions of the starch granule. Scanning electron microscopy showed that cross linking hindered amylose exudation. The stable hot paste viscosities of cross‐linked starches would be of value where low pH and high temperature are employed during pressure cooking or sterilization while the low degree of set‐back of field pea starch should improve the freeze‐thaw stability and textural quality of frozen foods.

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Section: Digestibility By A-amylasementioning

confidence: 99%

Effect of Cross‐Linking on Functional Properties of Legume Starches

1986

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“…The use of ECH to crosslink amylose was reported by Luby and Kuniak. 11 This methodology has been adapted to crosslink chitosan films and, in this work, fibers. Most notably, crosslinking by ECH considerably improves the strength of chitosan films and fibers.…”

Section: Introductionmentioning

confidence: 99%

Fiber formation and physical properties of chitosan fiber crosslinked by epichlorohydrin in a wet spinning system: The effect of the concentration of the crosslinking agent epichlorohydrin

Lee

Park

Choi

2004

J of Applied Polymer Sci

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ABSTRACT:The wet spinning of chitosan fibers was studied with 2% acetic acid as the solvent, 10% aqueous sodium hydroxide as the nonsolvent, and a 4% chitosan solution as the polymer. This article describes the crosslinking of the chitosan fibers. Epichlorohydrin (ECH) was selected as a convenient base-catalyzed crosslinking agent. The coagulation and crosslinking of the chitosan fibers occurred simultaneously in the coagulation bath. In this study, we investigated the effect of the concentration of the crosslinking agent, ECH, in the spinning dope on the structural, thermal, morphological, and mechanical properties (e.g., the tenacity, elongation, and work of rupture) of chitosan fibers. The tenacity of the chitosan fibers, especially the wet tenacity, was improved by crosslinking.

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Crosslinking statistics, 3. Relation between relative reactivity and accessibility of cellulose hydroxyl groups

1979

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From the results of a structural analysis of cellulose crosslinked by a bifunctional reagent conclusions can be drawn merely on the distribution of crosslinks among individual hydroxyl groups. No information is available to what extent this distribution is caused either by different relative reactivities ofthe hydroxyl groups or incomplete accessibility of glucose units. If each glucose unit had the same chance of reaction, at low levels of conversion only monosubstituted units should be present in the reaction product. If, however, some higher substituted units are present, this means that at a certain level ofconversion there must have been a smaller number of units capable of reaction to which relatively more reagent had access. The relation between relative reactivity and accessibility of cellulose hydroxyl groups obeys certain statistical laws of random selection. A theory explaining these laws is developed in the present work and supported by good agreement with experimental results exemplified by microcrystalline cellulose crosslinked by epichlorohydrin (1 -chloro-2,3-epoxypropane). The relative reactivities of cellulose hydroxyls were found to increase in the order OH-3, OH-6, OH-2 in the crosslinking reaction with epichlorohydrin. dl Part 2: cf.'). h, Systematic IUPAC name: l-chloro-2,3-epoxypropane.

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Crosslinking statistics, 2. Relative reactivities of amylose hydroxyl groups

Cited by 13 publications

References 18 publications

Effect of Cross‐Linking on Functional Properties of Legume Starches

Effect of Cross‐Linking on Functional Properties of Legume Starches

Fiber formation and physical properties of chitosan fiber crosslinked by epichlorohydrin in a wet spinning system: The effect of the concentration of the crosslinking agent epichlorohydrin

Crosslinking statistics, 3. Relation between relative reactivity and accessibility of cellulose hydroxyl groups

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