Fats as the carrier of taste

‘Fats as the carrier of taste ’ - many people will think here immediately of the few drops of olive oil mixed in a salad or the small amount of cream added to a soup. Fats are indeed important for the way in which the taste of a product is perceived, whether the fats are visible or invisible. It is then logical that reducing the amount of fat or changing the fatty acid composition has consequences for the taste. This applies both to the ‘own’ taste of a product as well as to the taste that is based on added flavouring. Because of the complexity of taste it is not easy to put forward general rules for how to develop a product with a different fatty acid composition while maintaining the taste. For the optimum result it will mostly be necessary to find custommade solutions.

Taste, smell and the way in which a taste is perceived

Taste and smell go together - these two are bound almost inseparably to each other. This is evident from descriptions of the words ‘flavour and flavouring’, which as well as ‘characteristic taste’ also mean ‘a substance that provides the smell and taste to food products'. The way in which taste is perceived is thus formed by a combination of tasting and smelling. People can distinguish tastes through the tongue and the cavity of the mouth and smells through the olfactory receptors in the nose.

Smells that are present in the air obviously reach the olfactory receptors through the nose. Smelling products awakens an expectation and triggers signals that prepare the body for taking in food. When you eat something aromatic substances are released during chewing and these proceed through the back of the throat to the olfactory receptors in the nose. This is called ‘retronasal smelling’.

In the first instance tastes are identified with the tongue. This is covered with a large number of papillae. Each papilla contains a number of receptors that allow people to perceive the different tastes. A number of receptors spread over the whole of the tongue are available for each taste. Four different tastes have been distinguished from of old: sweet, sour, salt and bitter. More recently it has been found that people have a fifth receptor that is sensitive to glutamate. This taste is called ‘umami’, which comes from Japanese and means ‘meatiness’ or ‘spicy’. A good Dutch translation is hartig or savoury. It increases the amount of saliva produced and enhances many other flavours as well as salt and sweet tastes. It is therefore for a good reason that such compounds are called taste enhancers.

Testing with test panels

PHOTO: NIZO food research, Ede The perception of taste takes place in the subconscious part of the brain which makes it very difficult to talk about taste. This is in contrast to how we see colours, for example, which does take place in the conscious part of the brain, close to the language centre. This is why most people can talk about colours easily, where this is much harder for tastes. Therefore, it can be useful to carry out taste testing using trained testers. These testers have learned how to put into words what they are perceiving. Trained testers are better able to separate the perception of taste as well as possible from other circumstances. Environmental factors after all play a major part in the perception of taste. On a cheerful sunny day people can taste things differently than on a sombre rainy day. A beer or a glass of wine when on holiday often tastes better than when at home after a stressful working day. Therefore, it is important that as much as possible taste tests are carried out under the same conditions.