November–December 2015 17
ILLUSTRATION BY ZOE LAWRENCE; TEXT AND RESEARCH BY MADELEINE VAN DER LINDEN
TOPOGR APHICAL
Accounting
for taste
The centre of the
tongue has few
tastebuds and is the
least sensitive to taste.
TONGUE
Palatine tonsil – tonsils Lingual tonsil
are masses of lymphoid
tissue that have a role
in the immune system.
Epiglottis – this directs
food into the esopha-
gus and away from the
trachea; it also has
tastebuds on it.
Circumvallate papil-
lae are at the back
of the tongue and
shaped in circles.
Fungiform papillae
on front of tongue.
Foliate papillae are
in ridges/grooves
towards the back
and sides of tongue.
Filiform papillae
are mostly on the
sides of tongue.
We each have up
to 10,000 tastebuds
on our tongue
“I
SN’T SHE SWEET”, “bitter old
man”, “He’s a good salt.” English is
littered with sayings relating to our
sense of taste. It’s one of the earliest senses,
developing 21 weeks after conception, and
is also one of the most powerful. There are
fi ve basic tastes: sweet; sour; salty; bitter;
and savoury, or umami (and perhaps now
a sixth – fat). The historic diagram that
shows the tongue divided into diff erent
regions responsible for each taste is in
fact a myth. All tastebuds detect all
fl avours, but the concentrations of cells
able to detect diff erent chemicals (sodium
chloride for salty, sucrose for sweet, for
example) varies across the tongue,
meaning that some fl avours appear
to be detected in diff erent regions fi rst.
SPICY
The ‘fl avours’ of hot
and spicy in chilli and
pepper are sensa-
tions, not tastes. The
chemical capsaicin
stimulates pain recep-
tors, producing the
impression of heat.
BABIES
Babies are born with
tastebuds not only on
their tongue, but all
over their mouth.
The tongue is covered with sensory
structures called papillae, which are
packed with hundreds of tastebuds and
come in a variety of types and shapes.
PAPILLAE
CORIANDER
Some people hate the
taste of coriander, but
it’s actually the smell
they don’t like.
Roughly 80% of
what we perceive to
be taste is actually
smell. When it comes
to coriander, some
people only smell the
bitter chemicals in the
herb, creating a nasty
taste in the mouth.
TASTEBUD
Tastebuds each contain separate cells that
pick out the fi ve different fl avours and their
levels of intensity as they wash over the
tongue in saliva. Each individual tastebud
only lives for about 10 days.
BITTER
Our dislike of bitter
tastes was developed
to stop us eating
poisons. Pregnant
women have a
heightened ability to
taste bitter things in
order to protect them
and the baby from
toxins. Breast milk has
a bitter inhibitor to
ensure that the baby
will drink it.
SUPERTASTERS?
Some people have a
greater concentration of
tastebuds, making them
‘supertasters’. They are
sensitive to bitter fl avours
from foods such as coffee
or broccoli and are more
likely to be fussy eaters –
although some scientists
have now contested the
supertaster theory.
UMAMI
Umami – also
known as ‘savoury’ –
is the fl avour of MSG,
glutamic acid or
aspartic acid and is
thought to be linked
to the overall protein
content of food.
Filiform papillae
Circumvallate papillae
There are still many chemi-
cal receptors on taste cells
that scientists don’t under-
stand. We may soon fi nd
taste receptors for sub-
stances such as fat, carbo-
hydrate, phosphorus and
calcium, says Professor
Russell Keast at Deakin
University in Melbourne.
NEW FLAVOURS