Episode 3 Food Detectives

Every day, we face a huge number of choices about food.

Everything from what we buy...

To whether it's good for us...

And how to cook it.

Beautiful.

In this series,

we're going to use our expertise to help you make the best food choices.

Wow! SHE LAUGHS

We want to improve your cooking...

-Well done, girl.

-It looks delicious.

..your health...

So, even if I've washed my hands, my forearms are still contaminated.

..and your bank balance.

So what are you getting when you spend extra money?

I'm scientist Alice Roberts.

I'll be looking at the latest research

into nutrition to find out what's good for us and what's not.

I'm journalist Sean Fletcher, I'll investigate which everyday

products are value for money and which are a rip-off.

And I'm chef Tom Kerridge.

And I'll be sharing my tricks of the trade

that I guarantee will fire up your taste buds.

Wow, that looks great.

'We're going to dish up the plain facts,

'so we can all enjoy our food more.'

-Cheers!

-Cheers.

-Cheers.

Coming up:

Why diet drinks may not be as good for our waistlines as we think...

-They're putting it away.

-They're polishing it off, it's disappearing.

..Tom reveals the store-cupboard staples no chef would be without...

Dust it with smoked paprika. That layer of smokiness works

so, so well with cheese. Stunning.

..Sean dissects the ingredients in tins of baked beans to find out

what we're really paying for...

It doesn't look like very nice stuff.

-Should we worry about this?

-Yes and no.

..and I'll find out how understanding the chemistry in our

kitchens can help give our food more life.

Onions make things like potatoes and other vegetables go off.

First up:

We spend a staggering £4.5 billion on diet drinks each year.

They now make up almost half of the fizzy drinks market.

But do diet drinks do what we expect them to do?

Do they help us keep the weight off?

A 330-millilitre bottle of a sugar-sweetened fizzy drink

contains around 140 calories, almost all of them from sugar.

The same size of diet fizzy drink contains almost 0 calories

and zero sugar. So how do artificial sweeteners work?

There are many different types of artificial sweeteners,

some of them are made from sugar, like sucralose, which is

a form of chemically modified sucrose,

others are synthesised in the lab from different compounds,

like aspartame.

But what all of these artificial sweeteners have in common

is the way that they trick our sense of taste.

# Sugar, I call my baby... #

To find out how they manipulate our senses,

I'm meeting Dr Caroline Withers.

So, if you put out your tongue, you can see

all the little bumps on the surface

and on those edges on the outside to those cells are the actual

receptors that can pick up the different tastes we have.

And for sweet, there's only one main receptor that they've found.

So you've got one single receptor that obviously sugar,

-glucose and sucralose interacts with?

-Mm-hm.

But artificial sweeteners are also interacting with that

with that receptor as well?

And I presume it must be like a key fitting into a lock.

If you can get a similar-shaped key in there...

-You can just about get away with it!

-Yeah.

These artificial sweeteners are so good at locking onto our taste buds,

that a little goes a long way.

So, if you take a sugar lump

and then you take an equivalent of actually one of these sweeteners

that you might get and if you take the pure sucralose, for example,

-that's 600 times sweeter than sugar...

-Really?

..so you need a fraction of that, really,

to get just as sweet as that sugar lump.

But what about the taste?

Caroline is putting me to the test with sugar

and some artificial sweeteners.

-So here are your four samples.

-OK.

So I think you should start on the right.

Yes, that's quite sweet. I don't think it's sugar.

-You don't think it's sugar?

-No.

-Why not?

-I'm not sure.

LAUGHTER

The first one is always the hardest.

So try the next one and then compare.

Mmm, that doesn't taste very sweet to me at all, that one.

It isn't going "Sugar!" LAUGHTER

SHE SIGHS IN EXASPERATION

I think that's the sugar.

-This one is the sugar.

-Really?!

We may think we can tell the difference between sugar

and sweeteners, but our taste buds are easily tricked.

So what I want to know is, if we're convinced that we're getting

sugar when we're not, what effect can this have on our appetite?

These athletes are performing an urban sport called parkour.

They're going to be taking part in an experiment to see if

artificial sweeteners can influence how much we eat after exercise.

-Hi.

-Hello.

'Overseeing the experiment is Professor Catherine Appleton

'from the University of Bournemouth.'

Absolutely brilliant to watch this,

but why are we watching parkour athletes?

Before we ask our participants to drink, we need them to be thirsty.

They certainly look like they're working up a thirst, don't they?

We've split them into a blue group and a white group.

-Are you all nice and thirsty?

-ALL: Yes.

To quench their thirst, the blue group is drinking

artificially sweetened drinks, while the white group

has the sugary variety.

ALL: Cheers!

And now, it's time for lunch.

Each table is laid out with the same number of calories.

We want to see which team eats more.

The blue group with their diet drinks or the white group,

with the sugary ones.

-They're polishing it off.

-They're putting it away.

-It's disappearing.

After exercising, each person is asked to eat

until they're comfortably full.

Has everybody finished?

The blue group, who drank the diet drinks,

didn't leave much food behind.

They ate a staggering 3,126 more calories than the white group,

who left behind a lot more food.

When you add the calories from the sugary drinks,

both groups' overall calorie consumption was about the same.

So what do scientists think is going on with the

artificially sweetened drinks that made the blue group eat more?

When you experience a taste, you expect energy to come afterwards.

With a diet drink, of course, you experience a taste,

but there's no subsequent energy.

Your body is prepared for energy, but it doesn't arrive.

Consequently, you become more hungry and you eat more.

So it's almost stimulating our appetite, then,

-but not rewarding us for it?

-Yes.

Other studies have found that there is a place for

low-calorie drinks in weight control.

But this research suggests that if you choose diet drinks after exercise,

you may end up eating more than you expected.

We're on a mission to improve the nation's cooking, one dish at a time.

Tom is keen to share what he knows

so that we can all raise the standard of our cooking.

I put a shout-out on social media for your kitchen fails.

It's clear there's a lot of you struggling with dishes

that don't always go the way you want them to.

But don't despair, I can help.

I've come to Glasgow to see if

I can save Gillian Bland from her kitchen disaster.

Yorkshire puddings.

LAUGHTER

Not quite cooked enough.

Risen and collapsed.

Tom, we need your help.

Right, time for the cavalry.

I'm sure with a few of my top tips,

I can whip sports manager Gillian's Yorkies into shape.

-Hey, Gillian.

-Hiya!

-Nice to see you. You all right?

-Problems with your Yorkshire puddings?

-Problems with Yorkshire puddings!

OK, let's have a little look.

Gillian is going to run me through how she normally cooks

her Yorkshire puddings, so that I can see where she's going wrong.

Starting with how she prepares her batter.

140g of flour.

Couple of eggs...and then just whisk it all in.

-Quite...dry and lumpy.

-Yeah, really dry and thick.

-SHE LAUGHS

-OK.

-So what I do now is put some milk in.

So you've got a big lump of flour and egg mix stuck in between the whisk.

-OK!

-LAUGHTER

That's not the way to make perfect batter.

Now, let's see how Gillian cooks her Yorkies.

-I normally leave them in there for 20 minutes or so.

-OK.

-Yep.

So what happens now? Do you have a little look?

-I try to not. Can't quite see through there!

-OK.

Look a bit pale still, so... I'll just shut the door back over.

It's a bit of a disaster.

Her Yorkies haven't risen properly and they're still doughy in the middle.

Right then, Gillian. Yorkshire pudding, my way.

The most important part of this Yorkshire pudding cookery

lesson is...using this, mate.

We've got to clean the oven and I'll tell you why,

it's because we need to be able to see in the oven,

-see what's happening without opening the oven door.

-Yes.

Because your opening the oven door changes the temperature

-and that doesn't help them rise.

-SHE LAUGHS

You're actually cleaning my oven, aren't you?

-Yeah, no, I am, actually!

-Actually!

SHE LAUGHS

Keep scrubbing there, Tom.

-That's it!

-LAUGHTER

-There we go, mate.

-Cheers, thank you very much.

-Oven cleaned.

Now that I can see what we're doing, I'm going to show

Gillian a simple method that will have her producing

light and fluffy Yorkshire puddings in no time.

Now, the first thing we're going to do is we're going to crack

-these four eggs into this bowl.

-Yep.

Not into the flour.

To get the best consistency for the batter, mix the eggs

and the milk together first, then add this mixture to the flour.

This will help prevent the batter from being overworked,

which can leave your Yorkshire pudding struggling to rise.

Just give it a last little mix...

So you just work the flour away from the sides.

-But you can see in that, that's still quite lumpy...

-Yeah.

Still quite thick.

Now, this is the really important point.

I'm going to put a bit of clingfilm on it

and I'm going to leave it to rest for a minimum of four hours.

Room temperature.

That sounds like a long time, but all the lumps and bumps will

dissolve and you'll end up with perfect Yorkshire pudding batter.

Now here's one that I made earlier.

We're going to heat these up in the oven and bring them

-up to temperature. But you can see these, these are deeper.

-Yeah.

Yours were very shallow, so they're going to be smaller, but taller.

-Yep, yep.

-We hope. Yep.

Use vegetable oil.

It doesn't have a strong taste,

so it's great for clean and crisp cooking.

Put the tray into the oven for 5-10 minutes to heat the oil up.

And this is where we pour the Yorkshire pudding mix in.

Now, when you poured your mix in, you poured it on to the side

-and it kind of dribbled in.

-Yes.

-Now you want to pour it dead centre.

-Right.

-And about halfway up, so it's creating a small well.

Then pop your tray into the oven and leave it alone.

Now, with Yorkshire puddings, you have to trust me on this

and be brave, do not be tempted to open that door.

Because if you open it too early, it will just kind of collapse, all right?

-Yeah.

-Like a pancake.

The heat in the oven creates air pockets in the batter,

causing the puddings to rise.

If you open the door midway through cooking, the oven suddenly

cools and the air pockets will collapse, leading to flat Yorkies.

-Here you go, mate. You happy with those?

-Happy with those.

-You made those.

-I can't believe just how different they are.

This is cooked all the way through.

-That means it's going to hold its shape.

-Yes, no soggy bottoms.

No soggy bottom. There's your first attempt.

-LAUGHING:

-So embarrassing!

If you feel that in weight.

It's like a doorstop!

# I like my baby's pudding... #

The perfect accompaniment, sausages and onion gravy.

There we go, mate, get in there and have a little try of it.

-Wow.

-A bit of a difference?

-Just a bit!

-Brilliant.

Yorkshire puddings, solved.

Share your kitchen fails on social media using

# BBCKitchenFails and I'll see if I can help you.

True or false?

When cooking pasta,

drizzle olive oil in the water to stop the pasta sticking.

The answer is false. Never put oil in the water, only salt.

It's the vigorous boiling of the water that keeps the pasta moving

so it doesn't stick.

Own brands are the rising stars in the supermarket.

You can choose from basic through standard to premium varieties.

But what exactly are we getting for our money?

When is it worth spending money on the premium

and when could a money-saving basic be just as good?

Our consumer journalist Sean Fletcher

is at Queen Margaret University in Edinburgh.

With help from food science experts, he's going

to dissect one of our all-time favourite foods.

Baked beans.

# Beans and coffee. #

In some supermarkets,

budget baked beans can be nearly 40 pence cheaper than premium.

So I'm hoping to find out what we're really paying for.

To do that, I've enlisted the help of some volunteers.

-So who buys basic and who buys premium?

-I buy basic.

-I buy basic.

Why would you buy basic?

I don't feel like it's worth paying the extra for, for the amount of taste difference.

I would probably buy premium.

-Do you notice the difference between the taste?

-I think I do.

Before we find out how different they do taste, nutritionist

Dr Carrie Ruxton is going to take us through the ingredients.

Carrie, what are the main differences between the price ranges?

There's not a huge amount of difference.

The main ingredient in baked beans is haricot beans

and they're the most expensive ingredient in the tin.

So the beans are the most expensive ingredient?

-So does that mean there are fewer of them in a budget tin?

-I don't know.

Let's count them.

So while Colin counts the beans in the budget tin,

Cath and Louise take on the standard

and Beth tots up the total in the premium organic beans,

we're going to look at what else ends up in your tin of beans.

The first three ingredients always tend to be beans, tomatoes, water.

Sugar also figures high on the list of ingredients,

with some budget ranges using a very different kind of sugar.

What you find that's different is in the budget ones,

there's something called glucose fructose syrup.

The reason they use that is because, first of all,

it's sweeter and concentrated, they can use less of it.

But the other thing is, it's in liquid form,

so it's a lot easier to pump into the can.

You don't have to dissolve it first.

Glucose fructose syrup is made from starch

and is much cheaper to produce than refined sugar.

It's pretty solid, isn't it?

Let's see what this is like.

-Hmm. It's really hard and sticky.

-SHE LAUGHS

And it's actually quite unpleasant. Should we worry about this?

Well, yes and no.

There are some experts who think that fructose causes liver fat,

but that's only if you eat vast amounts.

Time to catch up with our bean-counters.

-Colin, you did the budget tin. How many beans were in that?

-About 350.

Cath and Louise, you did the standard tin,

-how many beans did you have?

-478.

-478?

So that's a huge amount more.

-So let's find out the premium tin. Beth?

-So I counted 383.

-383?

So you're better off going standard, if it's all about beans.

Beth, Louise and Cath, you all buy budget.

-Will this change your opinion?

-Probably, yeah.

Because you're maybe going up one level for getting more

beans for your money.

It's only a small sample,

so not a definitive test of how many beans are in every cam.

But today, standard is the clear winner on quantity.

Now, what about the taste?

Our volunteers will try ten different baked bean samples

from a range of UK supermarkets.

There are four basic, four standard and two premium organic beans to try.

It's a blind taste test,

so no-one knows whether they're eating a cheap or expensive kind.

In charge is Dr Laura Wyness.

Standard came out on top for ingredients, but what about taste?

So, Laura, is budget better, standard or premium?

Well, actually, in terms of taste, the budget scored the highest

with 5.1 out of nine, closely followed by the standard,

at 5.0 and then finally, the premium was 3.6.

Although standard had the most beans,

when it comes to taste, budget was the favourite.

Wow. That's a real surprise.

So, Colin, you're a buyer of premium products.

Has that changed your perspective on this?

-It made me think.

-And what are you thinking?

-I'm thinking pennies, maybe.

-Save the pennies?

-Save the pennies, yeah.

-Beth?

I think it may be worth switching to the standard instead of the budget

-beans.

-And what about going premium?

-No.

So if you want to save money on supermarket own brand beans,

you're not giving up much nutritionally

if you downgrade to standard or budget,

and you'll have a lot more money left in your pocket.

We throw away 7 million tonnes of

food and drink from our homes every year in the UK.

Much of it is food we could have eaten.

Recently, the issue of food waste has become really big news.

So we can all do with a little help to cut waste.

At the heart of the kitchen, there's some clever chemistry at work,

and I want to discover how we can use it to make our food last longer.

To find out, we've set up our own

kitchen in this Glasgow shopping centre.

I want to know what the locals think

are the dos and don'ts of storing food.

What about potatoes? Would you keep them out in the light?

-No.

-Or do you think it is important to keep them in the dark?

-Important to keep them in the dark.

-Why, why?

-God knows.

-What about tomatoes, where do they go?

I would put them in the refrigerator, on the bottom shelf.

What about potatoes, where'd you keep those?

-We eat them all.

-You eat them?

Dr Patrick Hickey is going to help me separate fact from fiction.

He is an expert on moulds.

First off, I want to find out how to

store some of our most popular fruit and veg, starting with these.

Patrick, what's special about bananas?

Well, by placing these bananas in with the other fruits,

it will actually speed up the ripening process.

When bananas ripen, they produce a gas called ethylene

which makes neighbouring fruit ripen faster.

But this is a chemical signal we can use to our advantage.

If I got a piece of unripe fruit

that I'm really wanting to eat in the next day or so,

if I put that close to bananas, that's going to make a difference?

Yeah, and it might even help if you put them in a paper bag

or in a Tupperware container. That's going to concentrate that gas.

The gas will build up and ripen them much faster.

It's not just bananas that produce this ripening gas.

Vegetables do it too.

And there's one that you don't want anywhere near your other veg.

Onions, a bit like the bananas, produce this ethylene gas.

-Right.

-That can make things like

potatoes and other vegetables go off.

Keep onions away from the rest of

your veg if you want them to last longer.

But if food has gone off, is it still safe to eat?

Would you eat those?

The only time I wouldn't eat it is with green.

-I would throw out the green.

-Would you eat that cheese?

-No.

-Disgusting.

-Disgusting.

Would you cut off the mould?

-I have done, yes.

-Because I think...

-But then, I am Scottish.

I'm guessing most people would

chuck out mouldy bread and cheese, but do we need to?

It looks hairy.

These little threads that are coming

out the surface of the bread, those are fungus.

And on the end of them, if you can make it out,

there are these little balls.

Each one of those tiny balls is actually a spore,

and those are the things that spread in the air

and land on the bread, germinate and start to grow into the bread,

so if the bread has got just a small amount of mould on the crusts

you can cut those crusts off.

Is there going to be mould in the bread that you just can't see?

You should always allow a bit extra,

so cut a good five or 10 millimetres deeper than the mould you can see.

What about cheese, then?

Would you cut off the mouldy bits and eat the not-mouldy bits

or should we be more cautious, do you think?

If it's a hard cheese, then it's usually OK to cut off.

But if it is something that looks like it has gone slimy or

if it's a soft cheese, something like a brie, I wouldn't bother.

With slightly mouldy bread and hard cheese,

I can simply cut off the mould and eat the rest.

But there's something else lurking in the larder that has

the potential to make you very ill indeed.

Everyone I asked is quite clear that they wouldn't eat green

potatoes, even if they didn't know why, so why is it so bad?

Well, when the potatoes start to turn green, the compound

in there that is poisonous to us is actually something called solanine.

Solanine is a natural pesticide,

which gets concentrated in the green areas, and is toxic to humans.

If you were to eat that, you'd be very ill indeed.

The best thing to do, cut those areas off,

cut any developing shoots off as well.

Yes, I tend to keep cutting until I'm sure that there's absolutely

no green left, and sometimes you end up with no potato,

but that's better than eating something that is green.

Yeah, just chuck it.

Potatoes can begin to sprout within a week

if stored at room temperature and exposed to light.

So keep them in a cool, dark cupboard.

Beyond the way our food looks and smells on the surface,

there is this incredible hidden world of chemistry and microbiology

in our kitchens, and understanding more about those processes

of ripening and decay might help us keep our food fresher for longer.

TOM: Dishing up great food doesn't have to be difficult.

I have loads of ways to transform your cooking.

In a professional kitchen, getting food consistently tasting

great relies on tips and techniques that have never failed.

Now, I'd like to share with you some of these trade secrets

that are easy to do, but incredibly effective.

I want to let you in on the store cupboard staples that,

as a professional chef, I wouldn't be without.

Now, I've got four ingredients that, on the face of it,

are very familiar. But that can transform a dish in seconds.

First, olive oil.

Now, this is cold-pressed, virgin olive oil, and this is fantastic.

A little bit of this goes a long, long way. It is full on in flavour.

Do not cook with it. Use this to finish dishes.

And the reason you don't cook with it is because all of that

lovely freshness, that green,

raw flavour that you get from olives,

that'll burn in the pan.

When overheated, olive oil can start to break down.

This gives food an unpleasant taste.

So chefs only use it as a dressing.

Mix it with these tomatoes, chopped shallots, and some chopped herbs,

and this is called sauce vierge.

Huge flavours, wonderfully clean, wonderfully fresh,

keeps everything really delicious.

Another store cupboard essential is flaky sea salt.

The flavour is really intense and delicious, but also texture.

It's got loads of crunch to it.

You can finish just about any dish with this,

including desserts.

The amazing crunch that comes from the salt in that lovely flavour,

absolutely delicious.

It is one of those new classics, salt caramel.

Now, a little trade secret that delivers a big punch

is this - smoked paprika.

That layer of smokiness works so, so well with cheese.

Put grated cheese on the top, dust it with smoked paprika,

and as it cooks, that kind of cheese and the fats melt out - stunning.

And you might think this final store cupboard essential is a bit odd.

It's anchovies.

Now, I know you lot will turn your nose up at these,

or a lot of you will, and they're the sort of thing that you

just pick off the top of a pizza.

Think about them in a different way.

They will enhance so many dishes

and just give this underlying savoury, salty flavour.

They'll add a salty hit to a spaghetti dish,

liven up a simple salad, or enrich a sauce, like this salsa verde.

Finely chopped up into little bits like this, and then spooned

onto a piece of roasted lamb gives a lovely, savoury, salty kick.

Absolutely delicious.

There you go, my friends.

Four store cupboard essentials that, as a professional chef,

I think every home should have.

You can find these trade secrets and more on the website.

ALICE: Next time - We're told processed meat causes cancer.

But just what is it that we should be worried about?

Well, I think we've definitely proved

the existence of nitrate in that piece of bacon.

Sean reveals what's really in mayonnaise.

I'm flabbergasted by how many ingredients there are.

I have never made home-made mayonnaise,

but I'm guessing you don't need all of this to make it.

And Tom rescues a risotto disaster.

Terrible already!