Being able to taste good food is a true blessing and we should be grateful that our sense of taste works properly to indulge ourselves in gastronomical ventures. If we are to be living in ancient or prehistoric times, our sense of taste could be the best survival tool as poisonous plants usually taste bitter and our tongues are able to help us recognize this potential poison. You are probably wondering to ask a doctor, “how does the sense of taste work?”.
Before knowing more of the ‘how’, we need to acknowledge the main character or the main organ that plays a big role in enabling us to taste which is the taste bud. Taste buds are clusters of taste receptor cells that are connected to many different nerve fibres and mostly exist on the small bumps on the tongue called papillae. Although most of the taste buds are on the tongue, there are also taste receptors found in the throat and in the gut but it does not work the exact same as the taste by the tongue.
The way the sense of taste works starts off by stimulation of taste cells by chemicals binding to its receptors. This activates the cell by protein changes within the taste cell. Such changes cause the taste cell to send substance messengers through the taste nerve fibre and ultimately transmitted to the brain. Once the brain receives the taste signals, it sends signals through the cranial nerve to the lower section of the brainstem. The taste signals then travel back to the part of the brain to be combined with smell signals, sometimes also with the touch or temperature signals. This provides sensory perception. Sensory perception causes a human to be able to identify the 5 basic qualities of taste.
In the old days, you probably heard that only specific zones on the tongue can taste sweet, sour, salty and bitter. Nowadays, it is known that all parts of the tongue can actually sense the 5 basic tastes well which includes a new identified taste called umami or often known as savoury. Although, with an exception, the back of the tongue is very sensitive to bitter taste. This protects humans from swallowing potential poisonous or spoiled substances before entering the throat. By now, you probably wonder why spicy is not included in the 5 basic tastes. Well, spicy is not a taste because it does not work on taste buds like the other basic taste does. Instead, the capsaicin contained in the spicy food binds to receptors of the tongue that detect heat and pain before the brain interprets it as pain sensation. Hence, the temporary numbness of the tongue or feeling the tongue is burning is the way our body reacts to hot spicy taste.
Have you wondered why when we have the flu or cold, we tend to taste the food bland even though it is our favourite meal? As our smell sensation is impaired, the food taste alone is not enough to enhance the perception of the food itself. A food texture and consistency also play an important role in how we perceive taste. Thicker food affects the taste by slowing the rate of aroma and flavour exiting the food while if the same food is made into liquid, the taste will be much stronger. This explains why we would prefer crisper food with fattier or saltier taste compared to soggy and mushy food which does not look so appetising. In essence, the way the sense of taste works is much more than just the basic taste detected by the tongue. Check our Hajj Vaccination Package.
References:
https://www.ncbi.nlm.nih.gov/books/NBK279408/
https://rabowen.org/hbooks/pathphys/digestion/pregastric/taste.html
https://www.science.org.au/curious/people-medicine/how-do-our-tastebuds-work
