U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

Frost grape polysaccharide (FGP), an emulsion-forming arabinogalactan gum from the stems of native north american grape species Vitis riparia Michx.

Neil P. J. Price, Karl E. Vermillion, Fred J. Eller, Steven F. Vaughn
Journal of Agricultural and Food Chemistry 2015 v.63 no.32 pp. 7286-7293
Vitis riparia, arabinogalactans, emulsifiers, emulsions, flavor, gels, glucuronic acid, grapefruits, grapes, gum arabic, molecular weight, nuclear magnetic resonance spectroscopy, oils, proteins, stems
A new arabinogalactan is described that is produced in large quantity from the cut stems of the North American grape species Vitis riparia (Frost grape). The sugar composition consists of L-arabinofuranose (L-Araf, 55.2 %) and D-galactopyranose (D-Galp 30.1%), with smaller components of D-xylose (11.2 %), D-mannose (3.5%), and glucuronic acid (GlcA, ~2%), the latter linked via a galactosyl residue. Permethylation identified 3-linked Galp residues, some substituted at the 2-position with Galp or Manp, terminal Araf and Xylp, and an internal 3-substituted Araf. NMR identified ßGalp and three aAraf spin systems, in a Araf-a1,3-Araf-a1,2-Araf-a1,2-Galp structural motif. Diffusion-ordered NMR showed that the FGP has a molecular weight of 1 - 10 MDa. Unlike gum arabic, the FGP does not contain a hydroxyproline-rich protein (AGP). FGP forms stable gels at >15 % w/v, and at 1 - 12% solutions are viscous, and are excellent emulsifiers of flavoring oils (grapefruit, clove, and lemongrass), giving stable emulsions for =72 hours. Lower concentrations (0.1% w/v) were less viscous, yet still gave stable grapefruit oil/water emulsions. Hence, FGP is a ß1,3-linked arabinogalactan with potential as a gum arabic replacement in the food and beverage industries.