Taste is one of five traditional senses present in human beings. Although all five are regarded as important for the total eating experience, not all are equally important as some are involved only in an indirect way.
Taste or gustatory perception, is the chemical sensation produced when a substance in the mouth reacts with receptors called taste buds.
Smell or olfaction constitutes the aroma cues produced by substances and picked up by receptors in the nose.
Sight informs us about the colours, general appearances and shapes of the substances we are about to consume, but little about its taste or smell.
Touch informs us about the texture of the substance, its temperature and in some cases, the pain it causes.
Hearing is perhaps the most distant of all five senses when it comes to the eating experience. Yet it tells us something about the textures (the crunch of deep-fried fish or a fresh apple for example) of the substance. More importantly however, it tells us a lot about the overall eating experience.
Close your eyes and think of the crashing waves at a beach-side restaurant, the buzz of a cozy restaurant filled with happy diners, the sounds of pots and pans and cutlery that tells us lunch is going to be ready soon. Makes you hungry does it not?
Researchers have found that even though the five senses differed in their modes of reception, all shared three common steps: 1) a physical stimulus, 2) a set of events that transform the stimulus into nerve impulses, and 3) a response to the signal that takes the form of a perception or conscious experience of sensation.
Yet, there is a qualitative difference between the physical properties of the stimulus and our perceptions. The nervous system extracts only certain elements of information from each stimulus, while ignoring others, and then interprets the information in the context of the brain’s intrinsic structure and, importantly, previous experience.
For example, we receive (as stimulus) electromagnetic waves of various frequencies, but we see the colours red, blue and green. We receive pressure waves from object vibrating at different frequencies but we hear words, music and sounds. Thus, what we perceive to be taste and smells are really nothing but chemical compounds floating on air or in water.
Tastes, like colours, smells and tones, are metal creations constructed by the brain out of sensory experiences. Therefore, they do not exist, outside the brain.
Taste are classified as aversive or appetitive depending on the potential effects of the substance to our bodies. This serves as an early warning system of sorts. For example, sweetness helps to identify energy-rich foods, and bitterness is associated with poisonous or toxic substances.
It is thus not surprising that bitterness is usually the last taste to be acquired and appreciated, as only repetition would allow the initial averse association to be set aside. It is thus not surprising that most if not all coffee drinkers started with sugar added to their coffee. Chocolate lovers typically start with the sugar rich, sweet variety before moving on the real (bitter) deal.
Taste receptors (as is the case with smell and hearing) are spatially distributed to form (taste) clusters on the tongue. The tongue is the primary location of taste buds, but the cheeks, roof of mouth and throat also have some. Each cluster of taste buds has particular chemical sensitivities (salts, sugars, acids, etc.) and their spatial activity allows the brain to differentiate between the various tastes of which we have five: salty, sweet, bitter, sour and umami.
The chemical processes for each of these taste groups do vary. Salty and sour flavous occur when salvia breaks down sodium or acids. Sweet and bitter involve many more chemical componets.
Different foods will excite specific combinations of these taste receptors to evoke their characteristic tastes. This is one element among several others that makes culinary traditions unique and easily distinguishable from others.
Unfortunately, we are not equal when it comes to ability to taste. Some are supertasters whilst others taste very little or nothing at all. So what can influence our ability to taste?
Genetic makeup does play a role as some people have more taste buds than others. Compared to some animals we have relatively few taste buds. Cows have about 25,000, rabbits 17,000 and us humans only 10,000. Within various human populations tested, the variance is great. Some were found to have as few as 11 taste buds per square inch, whilst other had a hundred times more.
Women generally have more taste buds than men, making them better tasters. Furthermore, we tend to taste better when we taste something we like.
Age plays a part too. Although we regenerate new taste buds to replace damaged ones every 3 to 10 days, older people replace theirs at a slower rate than say children. They would thus require much more flavour substances (spiciness or sweetness for example) than a child eating the same food.
The amount of salt that naturally occurs in our saliva is another factor that influences our ability to taste. Those with less will taste the saltiness of food more intense, whereas other would have to add some salt.
Another important factor is the quality of our smell. As the food that we eat produce odor that reaches the nose through the nasopharynx (the link between the nose and mouth), and since the smell is more sensitive to odors than taste is to flavours, any person with a smell deficiency is less likely to taste food properly.
This means that having a flu or a cold, or flying in an aeroplane or sitting in an air-conditioned room, or any other location where the nose is dried out, will make food taste less intense. Ever wondered why your Air Namibia meal is so tasteless? Well, that is one possible reason (other than the flavour profile of the meal to start with). It is the lack of smell that hinders the brain’s ability to interpret flavour, not your taste buds.
This means that it is often difficult to determine whether taste deficiencies are smell or taste bud related. Either one or both deficiencies are potentially dangerous as eaters are stripped of their early warning systems that guard against obvious food poisoning. Not being able to taste or smell has a severe effect on some people, causing metal and emotional distress and discomfort.
Other than diseases that cause swollen mucus membranes (such as a cold, flu or allergies), neurological diseases such as Altzheimer’s and Parkinson’s disease also reduces the brain’s ability to interpret flavour, as does prolonged exposure to environmental toxins and certain enzyme inhibiting drugs.
Tastes can be acquired. Think of the first time you had a raw oyster, sushi or sashimi. It blew your mind, quite literally, didn’t it? Yet, over time, your brain created a perception or flavour profile for it, and chances are today, that you’d eat it whenever you get the opportunity.
As food and culinary traditions travel and our exposure to it increases, few things remain that would blow our mind. Your best bet is to explore molecular cuisine where everything is designed to defy and trick your senses. As for this week’s dish, it has no such intent. It was designed to prove comfort to someone with pain. As for you, it would fit your brain’s construct of a slow home cooked meal. You’ll recognize the flavours immediately, and you’ll be comfortable with them. Provided that your smell is not impeded, that is.