Reduced-molecular-weight derivatives of frost grape polysaccharide

A new Type II arabinogalactan was recently described as an abundant gum exudate from stems of wild frost grape ( Vitus riparia Michx.). The purpose of the current study is to more thoroughly characterize the physical properties of this frost grape polysaccharide (FGP), and develop methods to modify the molecular weight of FGP for potential new applications. Specifically, native FGP was modified by heat treatment, digestion with the enzyme L-arabinosidase, and ultrasonication. Results showed that native FGP was progressively and irreversibly denatured by heat treatment, while the polymer remained largely resistant to enzymatic digestion. However, ultrasonication reduced the molecular weight of FGP from 1.6 × 10 7 Da to about 3.0 × 10 5 Da. Reduced-molecular-weight FGP exhibited modified solution viscosity properties, which could be useful in food and prebiotic applications.