Why people make a funny face after biting lemon

August 31, 2024

Ever wondered why your face automatically scrunches up after taking a bite of a lemon or even thinking about it?

It's a universal reaction, one that transcends cultures and geographies, and it's all thanks to the fascinating interplay between our taste buds and the natural compounds found in lemons.

Let's dive into the tangy world of lemons to understand the cause behind this sour sensation that has intrigued scientists and food enthusiasts alike.

At the heart of a lemon's sour power is citric acid, a natural preservative and the predominant acid in lemons, comprising up to 8 per cent of the dry weight of the fruit.

Citric acid is what gives lemons their characteristically sharp, tangy taste. But the reaction it triggers goes beyond mere taste—it's a full sensory experience that involves our taste buds, facial muscles, and even our brain.

Humans have approximately 10,000 taste buds, each equipped to detect the five basic tastes: sweet, salty, bitter, sour, and umami.

When citric acid from a lemon enters the mouth, it specifically stimulates the taste buds responsible for detecting sourness.

These taste receptors, known as Type III taste cells, send a signal directly to the brain, alerting it to the presence of acidity.

The facial expression we make when tasting something sour, often referred to as the 'sour face,' is actually a reflex action.

This grimace, characterized by squinting eyes and a puckered mouth, is thought to be an involuntary reaction aimed at protecting our mouth and body from potentially harmful acidic substances.

It's as if our body is saying, 'Beware, something strong this way comes!'

The role of genetics

Interestingly, not everyone's sour face is created equal. Research indicates that genetic variations can influence how intensely we perceive sour flavours.

Some individuals are more sensitive to sour tastes due to a higher density of specific types of taste receptors, resulting in a more pronounced reaction to the same stimulus.

The sour sensation of lemons can also stimulate saliva production, aiding in digestion and improving oral health.

This content was generated by an AI model and verified by the author

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