All you need to know about food, flavours, taste and how to tickle those taste buds

There are so many varieties of foods and flavours out there, yet we all experience them differently. Have you ever wondered how this works and why some people prefer and dislike certain foods?

Here, nutritionist Laurann O’Reilly and owner of Nutrition by Laurann, explains everything we need to know about food, flavours, taste and how to tickle those taste buds.

- Are taste and flavour the same thing? Taste refers to the perception of the sensory cells in your taste buds. When food compounds activate these sensory cells, your brain detects a taste, like sweetness. Whilst flavour includes taste and odour. Odour comes from your sense of smell.
Sensory cells in your nose interact with odour particles, then send messages to your brain.

- What Are Taste Buds? The surface of our tongue is covered with tiny bumps called ‘papillae’, which contain our taste buds and also some glands that help in the creation and secretion of saliva. There are four different types of papillae, which come in different shapes and sizes and can be found in different regions of our tongue in varying numbers. What most of them have in common though, is the taste buds they contain.

- How Many Taste Buds Have We? The human tongue contains approximately 2,000 to 8,000 taste buds, which means that there are hundreds of thousands of receptor cells. The sensory cells in the taste buds which are responsible for how we perceive taste and renew themselves weekly.

- How Do Our Taste Buds Differ? Approximately a quarter of the population are considered ‘super-tasters’. These are people with a heightened sense of taste, particularly for bitter foods. Whilst another quarter of the population are considered ‘sub-tasters’ who can taste foods but are less sensitive and cannot detect such a bitter taste.

The number of taste buds varies widely for each person. Some people may have only a few individual taste buds, whereas others may have several thousand. This variability can determine the differences in the taste sensations experienced by different people.

Taste sensations produced within an individual taste bud also vary, since each taste bud typically contains receptor cells that respond to distinct chemical stimuli. This results in the sensation of different tastes which are salty, sweet, sour, bitter and umami (savoury). Let’s look at them a little deeper.

1) Sweet: Sweetness is caused by the presence of sugar or substances that mimic sugar. Certain proteins may also taste sweet. Scientists think we evolved to like sweetness because it helps us recognize energy-dense foods. Sweet foods are often high in carbohydrates, like glucose, which provide our bodies with fuel. Sweet can also work well combined with other tastes, for instance the sweet and salty combo.
Sweet Examples: Honey, fruit juices, fruits such as berries, high sugar foods such as sweets or cakes and milk chocolate

2) Sour: Sourness, or tartness is a taste that detects acidity. This taste helps us to detect food ripeness or if it’s ‘gone off’. As spoiled or rotten foods can also taste sour, it is thought that we evolved to taste sourness to identify these toxic foods. However, there are plenty of healthy nutritious foods which also have a sour taste. Sour foods work well when combined with other tastes, for instance sweet and sour tastes can often complement each other.
Sour Examples: Vinegar, citrus fruits such as lemons, limes or oranges, yoghurts, wine, sour sweets and fermented foods such as sauerkraut.

3) Salty: Saltiness is usually caused by table salt, or sodium chloride that’s added to food as a flavour enhancer. It can also be caused by mineral salts. Sodium is essential for electrolyte and fluid balance. However high intakes of salt can also cause increased blood pressure so should be used and consumed sparingly.
Salty Examples: Soy sauce, pickled, preserved or fermented foods and processed foods

4) Bitter: Bitterness is due to the interaction of many different molecules, which give a sharp taste and is the most sensitive of the 5 tastes. Our ancestors evolved to taste bitterness so they could recognize and avoid toxic substances which are often bitter. However not all bitterness is bad and there are plenty of healthy and delicious bitter foods, in fact bitterness can make foods that little more interesting. There are also some antioxidants (disease protecting compounds) which have a bitter taste such as those found in coffee and dark chocolate. Most of us tolerate bitterness at low amounts or when the bitter foods are combined with other tastes.
Bitter Examples: Coffee, dark chocolate (unsweetened cocoa bean), citrus peel, beer hops and tonic water (quinine)

5) Savoury or Umami: Umami is the most recently discovered taste. It’s a Japanese term that roughly translates to “savoury” or “meaty” in English. In 1908, a Japanese researcher found a unique savoury taste in a type of seaweed. He determined that the seaweed’s savoury taste was due to the salts of glutamic acid. Umami includes aspartic acid monosodium glutamate or MSG which is commonly found in many of the foods we eat today (such as that savoury tangy taste that we get from a bag of crisps for instance). MSG provides its strongest taste when combined with foods such as meats, fish, nuts and mushrooms. Since this initial discovery, umami substances have been identified in a range of other foods and umami was finally accepted as a new taste when scientists found umami receptors in our taste buds. Interestingly, it’s been found that some savoury taste buds respond to glutamate the same way that sweet taste buds respond to sugar.
Savoury or Umami Examples: seafood, meats, aged cheeses, seaweeds, soy foods, mushrooms, tomatoes and kimchi

- Does The Tongue Have Different Taste Zones? Many of us grew up believing the tongue, but this is not the case. The different tastes can be sensed on all parts of the tongue. However, the sides of the tongue are more sensitive overall than the middle, and the back of our tongue is more sensitive to bitter tastes

- What Else Affects Our Taste?

- How Food Smells: The way a food smells is also important to our overall eating experience. As we chew, volatile compounds are released and travel from the back of our mouths to our noses, where they stimulate our olfactory system. Without this, much of the flavour of the food we’re eating is missed, as opposed to just what is perceived by our taste buds.

- Reactions To Certain Foods: Certain proteins are activated by heat for instance capsaicin (hot chillies), piperine (black pepper) and hot mustards giving us that hot sensation. Whilst others are triggered when we eat cold foods like ice cream, foods with menthol, mint or eucalyptus flavours causing the that cold refreshing feeling we get after we eat them.

- The Texture of Food: The consistency or how it feels in our mouths is also important to how we perceive its taste and whether we like it. Scientists have spent a lot of time investigating rheology (the way liquid matter flows) and tribology (how oils and fats lubricate both the food and our mouths as we eat) to understand how these factors affect people’s food preferences.

- Unique Taste Disorders:
Dysgeusia: Otherwise known as phantom taste perception is the most common taste disorder. It is characterised by a lingering taste, often bitter or sour, even when there is nothing in your mouth.
Hypogeusia: is when a person has a reduced ability to taste things. A complete lack of ability to taste anything is called ‘ageusia’. True taste loss is rare. Often an inability to taste is related to a loss of smell due to congestion.

If you or someone you know is experiencing any taste related issues or are experiencing unfamiliar tastes please contact your GP who can assist you.