Chemistry Reference
In-Depth Information
Nasal cavity
Palate
Oral cavity
Velum
Pharynx
Lips
Tongue
Epiglottis
Larynx opening
into pharynx
Jaw
Oesophagus
Larynx
Fig. 9.2
Schematic representation of the oral cavity. Reprinted from Chen (2009), copy-
right 2009, with permission from Elsevier.
videofluorographic studies, the time spent for different types of foods
has been measured. Irrespective of the food type, stage I transport lasted
for about 2 seconds; stage II, depending on the product type, lasted
between 8 and 20 seconds, with the time increasing with the 'hardness'
of the product (Hiiemae and Palmer, 1999).
Hutchings and Lillford (1988) introduced a 'mouth process model'
for analysing the breakdown of typical foods during eating. The authors
identified criteria for swallowing based on the degree of structure reduc-
tion and lubrication. It appears that the overall preference within a class
of foods (e.g. baked products) relates to samples that are swallowed in
the smallest time.
In-mouth behaviour of soft solids (agar and gelatin gels) was inves-
tigated in humans by Arai and Yamada (1993). It was found that by in-
creasing the hardness of the tested samples, oral manipulation changed
from compression, between the tongue and hard palate, to shearing,
