Chemistry Reference
In-Depth Information
10
Rheological Control and
Understanding Necessary to
Formulate Healthy Everyday Foods
Ian T. Norton, Abigail B. Norton, Fotios Spyropoulos,
Benjamin J. D. Le Reverend and Philip Cox
10.1
INTRODUCTION
There is clear evidence that the consumption of high calorific and/or
salty diets leads to chronic diseases such as obesity, type II diabetes
and hypertension (Dahl, 2005). However, most people are reluctant to
change their dietary habits.
This gives the formulation scientist (microstructural engineer) an op-
portunity to develop the science and understanding necessary to produce
high quality everyday foods with lower calories and salt, but with all the
qualities and consumer perception of the unhealthy food (Le Reverend
et al
., 2009; Norton
et al
., 2006b). One of the major tools available is
rheological measurements/materials measurement. However, in order to
understand the product and redesign it to be healthier and still acceptable
to the consumer, no one technique can be used alone. So, from a practical
standpoint, a range of techniques are used to get an understanding of the
products and how different parameters relate to consumer response. For
instance, in order to understand what happens in the mouth, we need to
use tribology, rheology, viscosity at a range of temperatures, yield val-
ues (creep compliance), Young's modulus and failure stress and strain.
For spreading, we need rheology, thin-film behaviour (tribology) and
compression tests; if a product is to be cooked, we need to measure the
relevant material properties at a range of temperatures.
A good example of the approach necessary to understand and then
gain detailed control of the rheological properties of food can be given
by considering mayonnaise. On the face of it, this is a simple food.
However, in order to formulate a product that can be considered to be a
healthy everyday food, what do we need to do? There are many low-fat
mayonnaise formulations in the market. However, they suffer in terms of
their acceptability because their textures are significantly different from
