Thread by @realscientists

So let's talk about sensory perception!

Basic sensory perception involves our 5 senses:
1. Smell
2. Sight
3. Touch
4. Taste
5. Hearing

You may say that all those don't influence how I perceive food but they do!

We know that smell & taste are influential but how do the others come in?

Touch can be done by our hands if we pick up food but it also accounts for how we perceive texture in our mouth!

But touch is super important in the way we experience food, this is why small children will like to pick up and poke unfamiliar or strange-looking food before they will put it in their mouth!

Have you ever thought that a food looked a bit iffy?

That's your sight coming into sensory perception. We don't want to eat things that don't look good.

If we're forced to eat it, we'll probably not like it cause we've already decided it's going to taste bad.

Sound is extremely important when eating crunchy foods - if we don't hear that crunch we're not going to like it.

There was a study where they got people to wear headphones playing loud music while they were eating crisps (chips to the US) & people thought the crisps were stale!

This also works for things like the snap of a chocolate bar, and the crisp sound of when you bite into a nice apple!

But we are also don't want a sound that's not supposed to be there... you definitely don't want to hear a crunch when biting into something soft!

So moving onto smell and taste, these work together to create the taste & flavour of food!

Taste is with our tongue and our tongue can only pick 5 tastes (that we know of!) which are sweet, salty, bitter, sour & umami!

Everything else we perceive as flavour is actually smell!

Some people think our tongue can also pick up fatty as a taste but other people think that is just a texture sensation.

Another possible taste people think we can pick up is metal. Have you ever thought that water tasted metallic?

Something I always get asked when I talk about flavour vs taste is what about spicy? That is not my nose, thats my mouth.

Well there's technically 2 types of spicy, one is in our mouth (Chilies) and the other is a nose sensation (Wasabi)!

But neither are tastes!

The mouth burning effect is cause by a component in chillies called Capsaicin. What this actually does is turns on all the nerves in the back of your mouth! These nerves send signals to your brain that your mouth is burning even though it's not!

If you put a thermometer in your mouth after eating chilies, you mouth would be at normal temperature!

It's all a trick played by capsaicin!

All foods taste & flavour compounds called volatiles (name for individual taste/flavour compounds) separate from the food and these are be light or heavy. The heavy volatiles stay on our tongue & we taste them!

The lighter volatiles float up the back of our mouth, to our nose & we smell them

When people say they are practically tasting the food they're smelling they are technically correct cause most of what we "taste" actually comes from smell & can be picked up by just smelling food!

Back to our other (main) type of spicy, wasabi.

The wasabi spicy is one of these light volatiles that is picked up by our nose which is why it can sometimes take a second to kick in!

Another type of spicy which is technically not a main type because we only knew about capisums as spicy for a LONG time is found in szechuan pepper

https://twitter.com/realscientists/status/1377014454446084096?s=19

All our other "tastes" that are not salt, sugar, bitter, sour or umami are actually flavours and are being perceived by our nose!

This is why we food tastes strange when we have a cold, our ability to perceive flavour is impacted!

What is umami?

All our other tastes are pretty much self explanatory but umami not so much.

Umami was discovered in Japan so they named it and it's a savoury taste think broth, soy sauce, fermented meats!

So those are how our basic taste play into how we percieve food but they don't work alone to create the sensory perception of food.

Psychology has a MAJOR impact

Is it familiar or similar to something we have eaten before, do we have memories associated with the food?

Memories can evoke emotions that we don't even recognise. If you come across a food that you remember fondly from your childhood, you are more likely to eat it but that food will rarely live up to the memory of how good it was then!

Even things like the colour and materials of plates/packaging food comes in, the type of lighting in the room, where we eating and who are eating with can have major impact on our eating experience!

And technically not a sense but our sense of time can also impact our sensory perception of food.

If you are chewing a piece of steak for a long time, what do you think of it? You think it's a tough steak right? Even if you didn't think that when you cut into & started chewing?

Okay I think that's all I have to post today!

Most of our sensory experience woth food comes from our 5 basic senses, they ALL play a part but psychology is huge too!