Chemistry Reference
In-Depth Information
100
Two-phase
80
60
One-phase
40
20
0
0
0.1
0.2
0.3
0.4
0.5
Xanthan (%)
Fig. 5.16
Phase diagram for xanthan compatibility with milk.
5.4.4
Xanthan and starch
Starches are very widely used in food, and addition of low levels of
xanthan gum to starch-based products can improve their properties.
Xanthan gum does not significantly affect the gelatinisation of the starch
but can inhibit retrogradation, making the starch solutions more stable.
Xanthan gum is also effective at improving the freeze-thaw stability
of starches by controlling syneresis (Arocus
et al.
, 2009). Xanthan is
widely used in baked goods where its benefits are seen as better water
retention and lower crumb firming during storage. The high viscosity
of the xanthan gum also helps with suspension of particulates such
as fruit and chocolate pieces during the baking process. This gives an
even distribution throughout the product. The viscoelastic properties
of the xanthan gum help to increase the volume through better crumb
structure. Xanthan gum can also reduce liquid separation (syruping) in
refrigerated doughs (Simsek, 2009).
5.5
FOOD PROCESSING AND ITS IMPACT ON XANTHAN
GUM FUNCTIONALITY
5.5.1
Thermal treatment
Heating of food products during their manufacture and/or prior to con-
sumption is common practice. Its purpose is to preserve the product
through destruction of the microorganisms and enzymes responsible
for spoilage and to improve the texture and palatability of the product.
The heat treatment can vary from cooking to sterilisation according to
the type of product and the shelf life required. Sterilisation refers to the
complete destruction of microorganisms, including spores, and typically
