Chemistry Reference
In-Depth Information
8
Relationship between Food Rheology
and Perception
John R. Mitchell and Bettina Wolf
8.1
INTRODUCTION
The study of the relationship between rheology and perception has a
long history. Studies in this area have two related objectives:
(i) Prediction of perception from instrumental rheological measure-
ments. There are clearly considerable practical advantages in using
instruments instead of sensory panels.
(ii) The development of an understanding of the relationship between
food structure and perception. Rheology is not the only tool that can
be used to help achieve this understanding, but it is an important
one.
Although not completely incompatible, food science and rheology of-
ten make less than satisfactory bedfellows (Mitchell, 1984). The reason
for this is that foods are generally inhomogeneous on quite large dis-
tance scales and many natural products, for example meat and fruits are
anisotropic. This makes the application and interpretation of fundamen-
tal rheological tests difficult. There is a long history of development and
use of empirical test methods particularly for quality control purposes.
In this context, readers might be interested in the short and slightly sad
paper written by Scott Blair (Blair, 1978), one of the founders of food
rheology.
A significant advance in the context of the aforementioned objective
(i) was the development of the Texture Profile by scientists working for
General Foods (Friedman
et al
., 1963; Szczesniak, 1963). This recog-
nised that food texture was multidimensional and aimed at building a
direct relationship between sensory and instrumental measurements of
these different dimensions. The instrumental approach was almost en-
tirely empirical. It involved the two bite test. The food was compressed
