Heat and pH stability of prebiotic arabinoxylooligosaccharides, xylooligosaccharides and fructooligosaccharides

The heat and pH stability of prebiotic non-digestible wheat bran-derived arabinoxylooligosaccharides (AXOS), xylooligosaccharides (XOS)-and chicory root inulin-derived fructooligosaccharides (FOS) were compared. Heat stability (at 100 and 121 °C) and shelf-life measurements (at 4 and 37 °C) revealed decomposition at alkaline pH (pH 11.0) for all three preparations tested. The short chain oligosaccharides, XOS and FOS (apparent peak molecular mass of 400 and 800 Da, respectively), were more sensitive to alkaline decomposition than were the longer chain AXOS (apparent peak molecular mass of 1500 Da), the latter being the result of the higher abundancy of reducing ends in short chain oligosaccharide preparations. At pH 2.0 and 3.0, hydrolysis of oligosaccharide linkages took place, with FOS being the most acid-sensitive component.