Respectin the Pectin

Respecting the pectin. Such a wonderfully powerful health resource.


Abstract

A simple procedure for determining the galacturonic acid and methanol contents of soluble and insoluble pectins, relying on enzymatic pectin hydrolysis and colorimetric quantification, is described. Pectin samples are incubated with a commercial pectinase preparation, Viscozyme, then the galacturonic acid content of the hydrolyzed pectin is quantified colorimetrically using a modification of the Cu reduction procedure originally described by Avigad and Milner. This modification, substituting the commonly used Folin-Ciocalteau reagent for the arsenic containing Nelson reagent, gives a response that is linear, sensitive, and selective for uronic acids over neutral sugars. This method also avoids the use of concentrated acids needed for the commonly used m-phenylphenol method. Methanol, released by the action of the pectin methylesterase found in the Viscozyme, is quantified using alcohol oxidase and Purpald. This combined enzymatic and colorimetric procedure correctly determined the galacturonic acid and methanol content of purified, soluble citrus pectin. Application of the procedure to water insoluble pectins was evaluated with water insoluble material from apples and oranges. In both cases good agreement was obtained between this method and commonly used methods based on chemical pectin hydrolysis. Good agreement between these procedures was also found in the analysis of both soluble and insoluble pectins from several tomato products.

PDF | Combined enzymatic and colorimetric method for determining the uronic acid and methylester content of pectin- Application to tomato products


Glucuronic Acid, a Precursor of Ascorbic Acid in Aspergillus niger

Galacturonic acid prepared from pectin can be used to synthesize vitamin C.

Chemical Formula: C6H10O7
Layman’s explanation: Galacturonic acid is the monobasic acid resulting from oxidation of the primary alcohol group of D-galactose to carboxyl. It is widely distributed as a constituent of pectins (compounds with heterogeneous grouping of acidic structural polysaccharides, found in fruit and vegetables), many plant gums, and mucilages (gummy substances obtained from certain plants, which are used as food stabilizers). Gums tend to be used as thickening and bulking agents in pharmaceutics, and they play a less obvious part in most plants. Once swallowed, their actions are no different from those of the mucilages. D-Galacturonic acid prepared from pectin can be used to synthesize vitamin C. Native pectin is a mixture of polysaccharides, with the major component a polymer of -D-galacturonic acid. Pectin has numerous other medical and pharmaceutical uses, for example in combination with plant hemicelluloses and lignin, may be useful dietary constituents in preventing coronary heart disease, diverticular disease, ulcerative colitis, and a variety of other Western diseases.


Anti-cancer activities of pH- or heat-modified pectin

 

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