Do you know that the mouth of a foetus can already have taste sensations ? Do you know the relationship between the taste system and the sense of smell ?

“5 senses for kids Foundation” takes you through the different stages of the development of taste in children. At the bottom of the page, you will also find fun activities to accompany your little one’s discovery of taste.

Taste perception

First of all, we need to clarify what we mean by “taste”. We often think that the taste of food is perceived in the mouth. Try the following experiment.

Practical exercise: Pinch your nose and bite (for example) a piece of chocolate for a few seconds. Observe the sensation, then open your nose to swallow. Notice the difference: a pinched nose has no “taste” ; when an open nose has taste !

As Brillat-Savarin wrote in 1825: “without the sense of smell, there is no complete tasting”.

When we chew some food, we release sapid (i.e. “tasty”) and volatile products.

The sapid products are perceived in the mouth. These are the “basic tastes” : sweet, salty, sour, bitter and umami (protein taste). Umami means “essence of deliciousness” in Japanese, and its taste is often described as the meaty, salty deliciousness that deepens the flavour.

The volatile odorants travel up the back of the throat (pharynx) and are perceived by the olfactory system in the nose.

If we close the “chimney” of the nose, we suppress the olfactory dimension. It is the whole of these perceptions that we call “taste”. This is why in the following we will use “gustation” for sensations in the mouth. It should be pointed out that the nerve pathways of smell and taste are different. The perception of taste is only formed in the brain when these two sensory pathways come together.

The sense of taste : what do we perceive in the mouth ?

We have talked about “basic tastes”. In fact, this is a far too simplistic notion. Let’s take the example of sweetness. It can be provided by sugar, which is practically pure sucrose. But many products are sweet substances, with varying degrees of sweetness, without sucrose: for example, sweeteners or fructose (the sugar found in fruit).

Taste : a multi-sensory experience

So there are countless products to stimulate our taste system. Moreover, as we eat mostly complex foods, made up of mixtures of palatable products, the resulting mouthfeel is ultimately much richer than the four ‘basic tastes’ would suggest.

Forget also about the supposed distribution of tastes on the tongue (e.g. sweet at the tip). These recent years research has shown that taste sensors are distributed in taste buds all over the surface of the tongue.

As with smell, the trigeminal nerve plays a role in taste. Its nerve endings detect temperature, texture, pungency (pepper), irritation (garlic), and the bubbles of soft drinks. And let’s not forget our auditory sense which “listens” to the sounds of chewing.

Taste during intrauterine life

How is the organ of taste formed in the foetus ? The taste sensors (receptors) are located on the surface of taste cells, which are themselves embedded in the taste buds, which are themselves assembled inside the papillae. A bit like a set of Russian dolls !

The taste buds appear to be functional from 3-4 months of gestation. Dutch researchers have been able to use ultrasound to observe some 19-week-old foetuses swallowing amniotic fluid. This movement becomes more widespread afterwards. It is therefore certain that the foetus can accumulate taste experience before birth.

A baby therefore comes into the world with olfacto-gustatory references that will evolve during breastfeeding.

The advantages of breastfeeding : a diet that adapts

There are three phases of lactation : colostrum, transitional milk and mature milk.

Colostrum is produced for 2-3 days after the birth. It is highly concentrated in proteins (23 g/litre) and oligosaccharides (12 g/litre) which, in addition to their nutritional contribution, act as probiotics favouring the implantation of the microbiota, largely inherited from the mother, which she has in a way “tamed”. Other components promote the baby’s immunity : antibodies and white blood cells. Colostrum is coloured yellow-orange by beta-carotene (or provitamin A).

Then comes the transitional milk; the composition changes and the volume increases to reach mature milk after about fifteen days. On average, each woman then produces 0.75 litres of milk per day and the baby takes 0.15-0.2 litres at each feeding. This milk is relatively dilute in protein (1%) but rich in carbohydrates (7%) and fat (4%), plus micronutrients (such as vitamins and growth factors).

As described in “Olfaction” in the part “For parents”, the olfacto-gustatory experience of breastfeeding, practised in the safe maternal environment, promotes both growth and learning. It will form the basis of the child‘s, and even the adult’s, food preferences and diversification. It is here that food traditions are anchored; when we eat, we also eat culture. For, until about the age of two, children experience the “golden age of taste buds”, when they have two essential abilities:

  • The first is their capacity to learn, which is all the more stimulated when new foods are presented in a familiar and reassuring context that encourages curiosity.
  • The second, which is lost after 3-4 years, is that babies know when to stop eating.

During pregnancy and the breastfeeding phase, “5 senses for kids Foundation” recommends that the mother have a balanced and diversified diet.

The diversity of food practiced in the family will have several repercussions on this learning process. Through the mother’s diet, a foetus and then a baby at the breast acquires a first founding experience. After weaning, family practice will also offer a greater or lesser variety that will continue throughout childhood and into adulthood despite episodes of ‘neophobia’ at first, and then of adolescence.

Food neophobia and adolescence

In the second year, a “distrust” of new foods (and even of known foods, perhaps simply because they are not eaten under the same conditions) sometimes develops, which is called neophobia. It is thought that, after the period of “total confidence” of the first few months, the newly acquired autonomy is accompanied by the usual reflex to novelty : distrust of something new that could be potentially harmful or dangerous. Doesn’t an adult show this reaction when presented with an unfamiliar dish ?

The child who “does not want to eat anything”

This is a parent’s nightmare. Researchers who have worked on neophobia suggest a series of tricks to overcome it.

Present the refused food several times in a row (8-10 times) without forcing it, involve the child in cooking, shopping, gardening, play games, organise school activities… Obviously, this can make life a little more complicated !

Adolescence is another period of major change. The nervous and hormonal systems are largely reworked and the company of friends means that new psycho-socio-cultural influences can challenge or modify habits. At all ages, in the brain, activities related to social conformity are found in the reward circuit (which functions in particular with dopamine). This means that the reward for conformity becomes greater (to a greater or lesser extent depending on the individual) than the reward for old preferences. Let’s not forget that humans are social animals, and the group’s food choices, even if they are bad, can be imposed by this means.

Do I like it or not ?

For children, the pleasure of eating involves various structures in the brain. The amygdala (not the amygdala in the throat, but an almond-shaped nerve nucleus) is part of the limbic system, the system of emotions and memories. The amygdala is in fact the “crossroads” of emotions, whether they are triggered by a sensory system or by the brain’s own activity. This means that we can recall the tasting of a food or a great wine with the same emotion as when we experienced it. The amygdala also plays a central role in the establishment of food aversions. If a dish has made us sick, this aversive memory can remain for a very long time and be awakened by the mere sight or smell of the food.

The culture of taste in France

In 2010, UNESCO included the “gastronomic meal of the French” in the intangible heritage of humanity. Since then, other food practices or productions around the world have received the same label. These cultural elements are all based on taste (olfaction + gustation) and it is certain that what is considered a good dish brings pleasure and well-being. Even if we must “consume in moderation”, olfacto-gustative education is worth giving it an important place for its consequences on health and well-being. The human species is probably the only species where a vital, fundamental need – to eat – has been able to be transformed into an art of living throughout its history.

Playful activities to awaken your child to different tastes

“5 senses for kids Foundation” recommends a few games to encourage your child’s taste development.

  • You can introduce a child to new textures with frozen yoghurt. Place a stick in a yoghurt and put it in your freezer. The child can then eat it like an ice cream.
  • You can also present a child with fruit in two different forms: pureed and in small pieces.

For children aged 3 or 4 :

  • As soon as children have sufficient understanding and sufficient confidence (because you will have to plug your nose), you will show them what to do for this test. The aim is to show that taste is a sense of smell. With a piece of chocolate or a spoonful of flavoured yoghurt: with eyes closed and nose pinched, we put the food in the mouth. Chew for a few seconds. Take the time to “feel” the sensation; then open your nose : what happens ?
  • You can also have children taste the basic flavours: salt, sugar (easy). More difficult: acid, lemon juice for example (children often don’t like it) and bitter such as endive (they like it less, but it depends on the children).