Taste the palate

How humans detect flavors

 

What is it that causes people to dislike particular foods when others prefer them?
This has been a puzzled for many chefs like me and others and troubled a whole spectrum of food producers, or even frustrated mothers with seemingly faddy children. Food and drink preferences - adding milk or sugar to tea or coffee, for example, or ketchup, vinegar or mayonnaise to chips- are partly social and cultural and are shaped by habit. There is, however, increasing evidence that our food preferences are also influenced by individual variations in taste perception- and since taste plays such an important role in flavor perception, these individual taste variations could help determine personal flavor preferences.
The human tongue can distinguish between salty, sweet, sour, and bitter.
Taste buds, which contain a number of taste cells, are located within taste papillae on the surface of the tongue.
As a food or drink is consumed, the taste molecules dissolve into saliva.
Taste transduction occurs when these chemicals contact the receptor sites or channels located at the tips of these taste cells in the correct orientation.
Originally the science believed that different areas of the human tongue responded to specific tastes. There are some slight differences in sensitivity across the tongue and palate; all tastes can be elicited from all regions of the tongue that contain taste buds.
Taste cells, like olfactory receptor neurons, are continually replaced throughout life, making the taste system particularly capable of withstanding ongoing exposure to stimuli.
Some people are particularly insensitive to one or more tastes.
Approximately 15-30 per cent of people cannot detect at all, and referred to as non -tasters, but the taster/ non taster frequency differs among ethnic groups.
There are variations on the variability of bitterness flavor.
People who can taste extremely bitter flavor are known, in the world of sensory science, as supertasters, while those who find it moderately bitter flavor are known as tasters.
A supertaster should not be thought of as individual who is better at tasting than non -taster. The term is simply refers to their intense perception of the bitter compound rather than the bitter taste in general.
In- fact there is many different bitter-tasting compounds exist.
A recent study results find approximately thirty genes encoding for the family of receptors that are responsible for recognizing bitter compounds, which suggests that there may be up to thirty receptors for bitter taste. It is thought that different receptors could be responsible for detection of different bitter compounds.
For example, it has been shown that, compared with non tasters, supertasters perceive sweet, sour, salty and bitter compounds more intensely, as well other mouth sensations such as the burn from chili peppers, black pepper, ginger and alcohol.
Environmental influences on likes and dislikes are well established-nausea, for example, can induce aversion for foods that were eaten shortly before the episode (sometimes even thought the food in questions didn't cause the nausea).
It is generally accepted that some alterations in taste occur as function of age, but the effects can be appears to be small.
Science has played an important role in furthering our understanding of flavor perception, Research techniques have been much improved over the last few years, with the invention of machines such as atmospheric pressure chemical ionization mass spectrometer (APCI-MS) to measure aroma release from foods and beverages; the liquid chromatography-mass spectrometer (LC-MS) to measure some of the textural properties of a food.
However, the most sensitive and valuable flavor-measuring "machine" is still people, who can describe the flavors they perceive as they eat a food.

Flavor problems

For a chef , a variety in taste senility poses a potential problem: if the chef responsible for seasoning a particular dish has a low sensitivity to salt yet a high senility to acid, this will probably affect the way he or she season the dish.
And how will a customer with a low sensitivity to sourness but high sensitivity to salt respond to such a dish? Even more importantly, what happens if the chef is a bitter-blind- how will a super taster respond to this dish?
Perhaps this goes some way to explain why different people prefer the cooking styles of some chefs to others.
A closer look at the raw data highlighted another interesting fact- how the same individual responding to the same solution on different test days responded differently.