Nomenclature
CAS number: 9000-69-5
Description and references
Polysaccharide substance present in cell walls
of all plant tissues which functions as an intercellular cementing
material. One of the richest sources of pectin is lemon or orange
rind which contains about 30% of this polysaccharide. Occurs naturally
as the partial methyl ester of α-(1→4) linked d-polygalacturonate
sequences interrupted with (1→2)-l-rhamnose residues. Neutral
sugars: d-galactose, l-arabinose, d-xylose
and l-fucose form side chains on the pectin molecule. Structure
studies: D. A. Rees, A. W. Wight, J. Chem.
Soc. B 1971, 1366. Secondary and tertiary
structure in solution and in gels: D. A. Rees, E. J. Welsh, Angew. Chem. Int. Ed. 16, 214
(1977). Review and bibliography: Towle, Christensen, in Industrial
Gums, R. L. Whistler, Ed. (Academic Press, New York, 2nd ed.,
1973) p 429-461. Book: Z. I. Kertesz, The
Pectic Substances (Interscience, New York, 1951).
Properties
Occurs as a coarse or fine powder, yellowish-white
in color, practically odorless, and with a mucilaginous taste. Almost
completely sol in 20 parts water, forming a viscous soln contg negatively
charged, very much hydrated particles. Acid to litmus. Insol in
alcohol or in diluted alcohol, and in other organic solvents. Dissolves
more readily in water, if first moistened with alcohol, glycerol or
sugar syrup, or if first mixed with 3 or more parts of sucrose. Stable
under mildly acidic conditions; more strongly acidic or basic conditions
cause depolymerization.Use
In the preparation of jellies and similar food products:
Owens
et al., “Factors Influencing Gelation with Pectin”
in
Natural Plant Hydrocolloids, Advances in
Chemistry Series (ACS, Washington, 1954) pp 10-15.
Therapeutic Category (Veterinary)
Antidiarrheal.