ABSTRACT
Xanthan, an industrial microbial gum produced by aerobic fermentation of
Xanthomonas campestris,
consists of a
β
-(164)- D-glucopyranose glucan backbone with side chains composed of (163)-
α
-linked D-mannopyranose-(261)-
β
-D-glucuronic acid-(461)-
β
-D-mannopyranose on alternate residues (Scheme X.72). The rheological properties of xanthan makes it an ideal emulsifier and thickener in foods, as well as in cosmetics and pharmaceuticals (Garcia-Ochoa et al., 2000). As a complex polysaccharide, it would be expected to have a low glycemic index. Sun and Griffiths (2000) reported that immobilization of
Bifidobacteria
on a novel, acid-stable bead made from gellan gum and xanthan gum significantly enhanced their tolerance to high-acid environments compared to the free cells when added to pasteurized yogurt and stored for five weeks at refrigerated temperatures. This technology could
be useful for delivering probiotic cultures to the gastrointestinal tract of humans and animals.
