Chemistry Reference
In-Depth Information
2.1
2
1.9
1.8
Wheat
Waxy maize
Modified waxy maize
HPMC
Water
HPMC data from Cook
et al.
(2003)
1.7
1.6
1.5
-0.25
0.25
0.75
1.25
1.75
log Kokini shear stress (Pa)
Fig. 8.3
Comparison of perceived flavour from Cook et al. (2003) data on banana-
flavoured sweet HPMC samples and data from a study on basil-flavoured savoury systems.
(Reproduced from Ferry et al., 2006a. Copyright 2006, with permission from Elsevier.)
were considered in the light of the Baines and Morris' studies and the
later work of Cook
et al.
, these starch-thickened products gave a much
better taste and flavour perception than would be expected based on the
ideas developed for the much more extensively studied 'linear' hydrocol-
loids. A possible mechanism which would support hypothesis (i) above,
first proposed by Baines and Morris for hydrocolloid-thickened systems
used for the results in Fig. 8.2, was that above the c
*
concentration,
mixing of the viscous solution (in the mouth with saliva) was restricted.
In the next section, the hypothesis that the difference between the per-
ception of high-viscosity starch-thickened and hydrocolloid-thickened
products is due to differences in mixing is explored.
8.4
MIXING, MICROSTRUCTURE, GELS AND MOUTHFEEL
8.4.1
Mixing
The better flavour perception from starch-thickened foods when com-
pared to those thickened by linear polysaccharides was confirmed in the
study by Ferry
et al
. (2006a), who compared hydroxypropylmethyl
cellulose and starch-thickened systems directly. Fig. 8.3 shows the
