The Secrets Of Your Food - First Season

How often do you stop and really think about your food?

Look at all this lovely fat and sugar. Yummy.

Do you ever wonder why you eat what you eat,

what cooking does to food...

Delicious.

...or what effect it has on your body?

I trained as a medical doctor,

and I'm absolutely obsessed by nutrition

and the hidden chemistry of food.

So I've teamed up with botanist James Wong to explore food,

each of us coming from very different perspectives.

Truly delicious.

Together, we have taken over the country's leading food science lab...

...to deconstruct some of our favourite foods...

It's all sunk to the bottom.

...and to reveal some truly remarkable secrets.

I want to find out what effect food has on us and our biology,

right down to the molecular level.

As a botanist, I am fascinated

by the massive diversity

of edible plants on our planet.

I'm gonna put them under the microscope

to discover exactly how their biology interacts with our own.

So, join us as we seek out

the most remarkable food stories on the planet

and reveal the hidden science of our food.

Flavour makes our food delicious.

Each flavour is a potent combination of aroma and taste molecules.

Get that combination right and food tastes heavenly.

But what IS taste?

Thai cuisine is particularly good

at exciting our full range of taste receptors

on one plate.

So, this is a Thai stir-fry, and I'm very fond of Thai.

There is, uh...

...a bit of fried chicken, lemon, garlic, onion.

A real sort of explosion of tastes.

And it's really strange to think

that all these sensations which are going on in my mouth at the moment

are generated by five simple tastes.

In front of me, I've got liquids

containing chemicals that will trigger these different tastes.

I have no idea which is which.

Salty. That's definitely salty.

Sweet.

That is sort of bitter, a bit like coffee.

And this...

is similar but more lemony and makes your mouth pucker up.

This is sour.

And this one is... really hard to describe.

This is the taste that has been most recently discovered.

This is umami.

The word 'umami' is a derivation of the Japanese

for 'a pleasant, savoury taste'.

And it is very, very strange to think

that every taste sensation you ever have

will consist of one or more of these tastes.

The sensations happen here - on the surface of the tongue.

Our tongue holds around 4,000 tastebuds.

Inside them are the five taste receptors.

In humans, this is where the taste begins.

And in this program, we'll show you how the food we eat

dazzles each of these receptors.

But why these five tastes?

And why is it that some combinations taste vile

and some taste utterly delicious?

We're going to travel the globe in search of the foods

that are particularly good at stimulating each taste...

Oh!

...and in the process, uncover how evolution

underpins our relationship with food.

To learn about the most unusual taste,

I've come to an extraordinary celebration

of our most popular fruit,

which is rich in umami.

I'm here in southern Spain

with about 20,000 other people to celebrate the tomato.

Welcome to La Tomatina

and the world's biggest food fight!

It's been running for over 70 years,

and it's thought it started with a street fight

that was so much fun, the locals decided

to do it again the next year, and the next.

As well as making a perfect food missile,

tomatoes carry a heavy punch of umami.

The trouble with being at the back is you get hit a lot!

But what exactly is umami

and why does it have such a powerful hold over us?

The answer lies inside the tomatoes.

To get at the umami, I'm going to blitz them...

...then spin them at high speed in a centrifuge,

filter,

then finally, stir and simmer to concentrate the taste.

After all that boiling down, this is all that's left,

and it no longer smells tomatoey at all,

because those volatile flavours have been boiled off.

And this stuff...

...doesn't taste tomatoey either.

It tastes... salty, earthy, meaty.

What my tongue is sensing is a chemical known as glutamate.

It's an amino acid,

a type of molecule derived from protein in the tomato.

Whenever you get a glutamate molecule in food,

it triggers that umami taste,

fuelling a desire for more umami-rich food.

It's our love of the glutamate in tomatoes

that has made them such an important crop for this region.

It's found here in the ancient oak forests of south-west Spain...

...home of the chunky local pig known as the 'pata negra'.

These pigs roam freely, foraging whatever they can find,

but their favourite treats are the acorns

that fall from the oaks every winter.

And it turns out that pigs and acorns are a match made in heaven.

Together, they make the most delicious -

and most expensive -

umami-packed ham in the world.

Iberico ham.

It's early morning in January.

Acorn season is coming to an end

and Juana Marquez is preparing

for one of the most important events of her year.

In this part of Spain, the annual killing of a pig is a major event.

It is known as a 'matanza',

and it involves the gathering of an entire family.

For Juana's pig, it's as respectful a death as you could hope for.

It will take the family the entire day

to turn 150 kilos of pig

into enough meat to keep them going all the year.

But butchering is only the prelude to transforming this meat

into an incredibly powerful umami-tasting explosion.

The secret to the intense umami taste begins

with the extraordinarily thick layer of fat...

...which comes from the acorns the pigs enjoyed in life.

The acorn fat from the local oak trees is rich in oleic acid,

the same fatty acid that's found in olives.

That's why the locals refer to the pigs as 'olives with legs'.

Walking olives that can eat up to 10 kilos of acorns a day.

Most hams end up here, in the darkness of an Iberian cellar.

This is where biochemistry kicks in and the exquisite umami taste forms.

The surface of the hams are under constant attack.

Microbes and oxygen in the air react with the fat on the outside,

making it yellow and rancid.

But the meat within is protected.

The acorn-fed fat layer is so thick,

it can keep the meat air-free for up to three years,

much longer than any other ham.

This allows the natural chemistry locked inside the flesh to unfold.

The meat starts to cure.

Over the years,

naturally occurring enzymes break the proteins in the meat down

into their basic building blocks - amino acids.

One of these is the all-important glutamate,

the molecule responsible for the taste of umami.

The longer meat cures, the greater the build-up of the glutamate

and the stronger the taste will become.

And time is exactly what its thick, fatty case provides each ham.

By the end, these hams have 50 times

the glutamate levels of fresh meat...

...making them the world's finest, meatiest,

most delicious umami-tasting hams.

It's a taste prized by charcuterie connoisseurs the world over.

But there's a biological reason

why we are drawn to the umami flavour of glutamate.

So, the reason... Mmm!

...why this ham is so delicious

is because glutamate is one of the building blocks of protein.

And protein is essential

to the building and running of every cell in our bodies.

So, what the ham is really saying to me

is, "Eat me, because I will make you big and strong."

And the way it sends that message is, of course, via my tastebuds.

As food enters the mouth, it meets the tongue,

a seething landscape of muscle covered by spiky papillae.

These help move each mouthful of food around.

As it swirls across the tongue,

the food comes across larger, dome-shaped papillae,

and here we find the tastebuds.

The glutamate enters each bud,

where it encounters the five taste receptors.

But the glutamate molecule has a distinctive shape

that can only activate the umami receptor,

sending a signal to the brain that tells us,

"Mmm. That mouthful of food is rather delicious."

We're hard-wired to enjoy the taste of umami

because it signals the protein we need to build our bodies.

But we can't survive on protein alone.

We would grind to a halt without a ready supply of energy.

So we have another taste receptor that fires off

whenever it encounters the chemicals that give us a quick energy hit.

Yum!

When you bite into a strawberry,

if you had to pick one word to describe its taste,

you would probably pick 'sweet',

and that's how our bodies detect the amount of sugar that's in fruit.

But sugar in nature seldom comes on its own.

It's usually balanced out by another taste -

the taste of acid.

I'm gonna show you that

with a fantastically geeky piece of kit here.

This is a pH meter