Extraction, purification and characterization of an arabinogalactan from frost (riverbank) grape (Vitis riparia Michx.) stems

This study investigated the extraction and properties of an arabinogalactan polysaccharide from frost grape (FGP) as a potential alternative to gum arabic (GA). Collection date, solvent:feed ratio (S:F), chip size, C-18 filtration, ultrafiltration, freeze drying versus spray drying, methanol pre-extraction, water absorption were examined. Sugar composition, elemental analysis, dietary fiber content, emulsification activity index (EAI), stability (ESI), viscosity used evaluate extracts. Exudates collected in March live stems viscous with high percentage solids FGP, while May collections watery low FGP. Frost collected, chipped, classified by size. The system utilized pressure or vacuum increase contact between chips water. A S:F ca. 24% gave excellent yield Chips 1.8 3.8 mm highest mass yields. Pre-extracting filtration extract both yielded lighter product. EAI for FGP was higher than that GA; however, its ESI lower. Ultrafiltration crude separated glucose, fructose, sucrose adsorbed became darker.