Chemistry Reference
In-Depth Information
MS-breath output
5.0E+06
4.5E+06
4.0E+06
3.5E+06
3.0E+06
2.5E+06
2.0E+06
1.5E+06
1.0E+06
5.0E+05
0.0E+00
Intake air
Flow from
nasal cavity
0
0.2
0.4 0.6
Time (minutes)
0.8
1
APcl probe
Blocked
liquid inlet
Nebulising gas
2-3 kV
N
2
Fig. 10.3
Schematic representation of the experimental set-up for measuring in-mouth
flavour release using APcI. Reproduced from Lian et al. (2004). Copyright 2004, with
permission from Elsevier.
limit of fat content in emulsion-based products of between 15 and 20%
gives acceptable performance on consumption. However, in the future,
it is to be expected that microstrucural elements such as particles of gel
or air-filled emulsion droplets will be designed to act like oil droplets,
allowing these limits to be changed. This is discussed more fully later
in the chapter.
The use of tribology should not be seen as a replacement for other
rheological and material measurements of what happens within the
human mouth, although the use of viscosity at 100 per second seems to
be of limited value for most food products, even though it has been used
extensively in the past.
The other aspect of the eating process that deserves consideration
from a material structure and rheological control point of view is flavour
release. If healthy everyday foods are to be acceptable to the consumer,
we need to control the flavour release and the after-taste of the reformu-
late food.
The material properties and the detailed food microstructure and its
breakdown in the mouth have been shown to affect the flavour of foods
(Hutchings and Lillford, 1988; Lillford, 2000). More recently, Lian
et al
. (2004) have started to develop models for the release process and
attempted to explain how the viscosity of a food influenced the mixing
in the mouth and subsequent flavour release. This was studied using the
MS breath technique, a schematic of which is shown in Fig. 10.3. In
