Chemistry Reference
In-Depth Information
Fig. 10.10
Photomicrograph of a duplex emulsion with the inner interface stabilised by
crystals (shell).
Very recently new work using shells has been carried out by Frasch-
Melnik
et al
. (2009). This work involved the use of crystallising triglyc-
erides that are placed at the interface for Pickering stabilisation and then
sintered together to produce an intact structure surrounding the droplet
(Fig. 10.10). As can be seen in this figure, the primary emulsion has
been produced to have a sub-micron size and then the secondary emul-
sion has a droplet size of about 10 µm. The crystalline structure, which
has been produced via a combination of crystallising mono- and triglyc-
erides, can be seen within the secondary droplets. Crystalline shells can
be seen around the primary droplets.
10
.
3
.
2
.
2
Salt reduction
One of the advantages of a duplex emulsion is that we can design in
two different water phases, i.e. w/o/w emulsion. This potentially gives
a structure that, for instance, could contain salt in the outer water phase
and no salt or KCl in the inner phase. The idea of the design is that the
consumer would be able to taste the salt contained in the outer water
phase when the food is eaten, while the inner water phase would go
undetected. This would result in a product, which is perceived as having
a higher salt content than is actually present. The extent of salt reduction
possible would depend on the ratio of the inner and outer water phases.
Some initial work by Malone
et al
. (2003b) demonstrated the potential
for this approach, although this work was in controlling acid perception.
