Tasting
Orange Juice after Cleaning the Teeth
Chapter
1: Science Aspects of Tasting Orange Juice after Cleaning the Teeth
In
this science project we will examine closely why according to the
book “Wie man mit einem Schokoriegel die Lichtgeschwindigkeit
misst” orange juice tastes so awful after cleaning the teeth
shortly before.
Have
you ever made this experience? You have overslept and you are in a
hurry. After cleaning your teeth you drink a glass of orange juice,
but the flavour of the juice is awfully bitter instead of sweet. And
then the whole breakfast may also taste disgusting. There’s
something wrong!
The
bitter taste of orange juice after cleaning the teeth with a certain
toothpaste is the consequence of the interaction of particular
substances. The juice of the oranges contains a lot of substances of
taste, among them there are bitter ones like the Limonin. The flavour
of the orange juice is sensed by taste receptors on the tongue and so
we can taste four kinds of flavour: sweet, sour, salty and bitter.
The respective receptors are not regularly divided on the tongue. The
sweet taste is in front of the tongue and the bitter one is in the
back sector, near the throat.
Toothpastes
contain water and different herb extracts like chamomile, Arnika,
Calendula, Hamamelis, myrrh, rosemary and sage. Beside other effects
they also affect the function of the taste receptors and cause a numb
sense on the tongue. In toothpastes there are often peppermint oils.
They contain much menthol and cause a cool freshness but numb sense
on the tongue, too. If you clean your teeth, the toothpaste
especially gets in touch with the front part of the tongue-body. The
taste receptors in the back part of the tongue, where you feel
bitterness, are quite less concerned than the receptors on the apex
which is responsible for the sweet taste.
Chapter
2: Tasting Orange Juice after Cleaning the Teeth – the experiment
Proceedings:
the project was done on 14th
June, 2012
Selection
of the experiment from the book “Wie man mit einem Schihriegel die
Lichtgeschwindigkeit misst”
Internet
research of the scientific topics
Organising
the paper: structure, pictures to be used
Carrying
out the experiment
Taking
pictures
Writing
the draft
Typing
of the paper
Proof
reading
What
I need:
Orange/apple
juice
A
toothbrush
3
kinds of toothpastes: 1. with ordinary mint
2.
with mint without a raising agent (available from health food shop)
3.
without mint
Experiment
report
The
purpose of this experiment is to find out why an orange juice tastes
bitter after cleaning the teeth with toothpaste shortly before. So I
will try to prove the maintained results as described in the book.
First
I took a mouth full of orange juice and I enjoyed its sweet and sour
flavor. Then I cleaned my teeth with a toothpaste which did not
contain any mint substances. After that I took another mouthful of
orange juice and tasted its flavor again. I repeated this process
twice: with a toothpaste that contained ordinary mint and another one
with mint but with out a raising agent.
Results
After
cleaning my teeth with a toothpaste, that did not contain any mint
products, the orange juice tasted sweet as before.
After
I had cleaned my teeth the second time with a minty tasting
toothpaste, I had bought in a health food shop, I took a mouthful of
orange juice but this time it tasted a bit strange but not so bad.
At
last I tried the toothpaste with ordinary mint and had some orange
juice shortly after. It tasted horrible like a bitter medicine.
Conclusions
Since
1970 people knew the so-called “orange juice effect”. A lot of
producers add raising agents to the toothpaste because they form
foam, divide better in the mouth and are easier to rinse out. But
this fact causes an awful side effect: these substances react with
the taste buds of the tongue and prevent the sensitivity for sweet
and salty food so that the bitter flavor is predominant. And the
strong additive of mint, which is required by lots of people, has
also an effect on that process. Its strong taste can leave a nasty
taste in the mouth so that you may not enjoy the breakfast shortly
afterwards. As a rule of thumb you should not clean your teeth before
the meal but - due to the mouth – after them.
Raising
agents are nit a necessary part of the toothpaste, but similar to
soap, people think that there is no benefit without forming foam.
People also do not believe in the effect of a toothpaste that has no
real taste of mint.
In
Japan, most toothpastes have a flavor of fruits and in the West,
toothpaste for children mostly do not have a minty taste but a fruit
one.