Episode 4 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.

We want to improve your cooking...

Well done, girl. 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.

That looks great.

We're going to dish up the plain facts

so we can all enjoy our food more.

-Cheers.

-Cheers.

Coming up:

Recently, there have been a lot of alarming headlines

about processed meat, but how worried should we be?

Tom tries to save another kitchen disaster.

It's terrible already!

It's not terrible, it's not, it's not, it's not.

Sean finds out what budget

and premium mayonnaises are really made of.

I'm flabbergasted by how many ingredients there are.

And I'll be revealing if aphrodisiacs actually work.

-I like your hair.

-Thank you very much.

His heart rate's gone up to 120.

First up...

MUSIC: Glory Box by Portishead

Last year, there was one particular story about food

and health that dominated the headlines

and it was the claim that processed meat causes cancer.

A World Health Organisation report described processed meat

as a group one carcinogen,

in the same category as asbestos, arsenic and cigarettes.

The story made headlines around the world.

Since the announcement and all of the subsequent press,

sales of bacon and sausages dropped dramatically by £25 million in this country.

So it's clear that many of us were scared off eating them.

So I want to get to the truth behind this story.

I want to find out just how dangerous

eating processed meat really is.

I've come to Reading University's Food and Nutritional Sciences Department.

I'm meeting Associate Professor Gunter Kuhnle

who's going to show me why processed meats have been linked to cancer.

We probably don't need a whole rasher, do we,

so I'll maybe just cut off the end of it there.

With this test, we should see something that's been added to the bacon.

A chemical at the heart of the debate surrounding processed meat.

If it's present, the liquid will turn pink.

Yeah, there's a pink tinge just starting to appear

-around the edges there.

-Very definitely

Ah, yes.

What's been detected is a preservative called sodium nitrite.

Well, I think we've definitely proved the existence of nitrite

-in that piece of bacon.

-Oh, yes.

Sodium nitrite is added to processed meat during the curing process,

which Gunter is going to show me.

So we have here a piece of bacon. We wrap it with curing salt,

which is really just table salt with a small amount of sodium nitrite.

Sodium nitrite kills the bacteria that can lead to botulism,

a deadly form of food poisoning.

It's a chemical that keeps us safe

but it's also responsible for the link to bowel cancer,

one of the most common types of cancer diagnosed in the UK.

This is really the problem with having nitrite in processed meat,

is that what, on one hand, preserves the meat causes on the other hand,

can cause cancer, can increase the risk of cancer.

The acidic conditions of the stomach are the perfect environment

for converting these nitrites into compounds that can cause cancer.

And so it makes sense that the link is to bowel cancer

because that's where these dangerous compounds are being formed,

actually in your gut as your food passes through you.

Another way of preserving meat is to smoke it.

Some of the chemicals released from cigarettes

are also generated by the meat smoking process.

They can stick to the surface of the meat

and have also been linked to bowel cancer.

Thanks to Gunter I've got a much better understanding now

of why processed meat poses a risk to our health.

There are potentially carcinogenic compounds present

in both cured and smoked meats.

But the World Health Organisation has placed processed meat

into the same category as smoking.

Both pose a definite risk in terms of developing cancer

but what about the level of that risk?

Does it mean eating processed meat is as bad for us

as smoking cigarettes?

To help me make sense of the statistics,

I'm meeting Dr Kathryn Bradbury from the University of Oxford.

She's an expert in how cancer affects populations.

So, Kathryn, looking at this new World Health Organisation

classification, what does it actually mean?

So, tobacco is much worse.

So we estimate that tobacco causes about 20% of all cancers,

whereas red and processed meat cause about 3% of all cancers.

How much processed meat are we talking about

and what is the relative risk?

Well, what we know is on average about six out of 100 people

in the UK will get bowel cancer over their lifetime,

and an extra 50 grams of processed meat,

which is about two rashers of bacon,

increases your risk of bowel cancer by 18%.

So is that eating that much bacon every day?

Yes, if we had 100 people,

six of them just normally would get bowel cancer over their lifetime.

If all of that group of 100 started eating an extra two rashers

of bacon every day, then we would expect that now

seven out of the 100 would get bowel cancer.

So that sounds like a relatively small increase in risk

when you put it like that.

Yes, I guess it does for 100 people, that's for sure,

but there's a lot more people in the UK, so we need to start multiplying

that up. It does translate into a lot more cases of cancer.

So if you're eating processed meat every day,

you increase your risk of bowel cancer by nearly 20%.

And it doesn't matter if you buy cheap or expensive processed meat,

the vast majority contains added nitrite.

Scientists are working on nitrite-free products

but as yet none are commercially available in the UK.

For the moment, if you eat a lot of processed meats,

it might be a good idea to cut down.

What this doesn't mean is that processed meat

is anywhere near as bad for you as smoking.

There is a small increased risk of cancer

but it depends on how much you eat and how often.

We want to improve the cooking skills of the nation

one dish at a time.

Tom's tips should help you to enhance your performance

in the kitchen, no matter how good a cook you already are.

I asked for your kitchen fails and you've sent me loads.

From disastrous poached eggs

to roast potatoes that no-one wants to eat.

This time I'm helping Tina Qureshi with her kitchen fail,

risotto.

I've been standing here for the last 25 minutes trying to cook

this thing, but it still looks uncooked.

There's quite a lot of rice here.

Looks like she's cooking enough for about 100 people!

So, Tom, show me how to make the perfect risotto.

We can solve this.

I've come to Bracknell in Berkshire to answer her cry for help.

-Hey, Tina.

-Hi, Tom.

-How are you, nice to see you.

-Few issues with your risotto.

-Yes.

OK, shall we see if we can fix it?

Please. Come through.

Tina's going to run me through how she normally cooks her risotto

so that I can see where she's going wrong.

So you're just using half an onion here.

Yes, I am. And I add the closed cap mushroom.

And, with that, I add the porcini mushroom,

that I soaked in hot water.

Where's the water that you soaked it in?

Ah, right, I threw it away. Can I actually use that?

What do you think that water would taste of?

Porcini mushroom. I should actually have saved that.

Are you dying inside, Tom?

No, no, no...

You're like what the hell is she doing?! Her pot's burning!

It's terrible already!

It's not terrible. It's not.

The method, the ideas that you've got. They're working...to a point.

Right, I'm going to add the rice now.

That's probably about 500 grams.

500 grams is quite a lot of rice.

For a decent main course allow about 100 grams of rice per person.

What Tina's got her here would feed a family of five.

OK, let me be straight with you.

It looks all all right, but there's nothing about that that's exciting.

By the end of today, we're going to have you making amazing risotto.

Kick off with some oil and butter.

I'm using shallot instead of onion because there is less acidity

so it's a sweeter flavour that goes through our risotto rice.

I'm going to use 200 grams of rice.

You used 500 grams of rice.

-That's double that.

-And give it a good stir.

I'm good at stirring.

You're good at stirring. You're going to be doing a lot of stirring.

Stirring releases starch from the rice.

This is what gives risotto that lovely creamy texture.

Now I'm going to pour in a massive glug of white wine,

and straight away, the starches, the white wine and the butter

all begin to mix together to make one kind of rich flavoured stock.

So now, instead of wasting it, all of this lovely mushroomy water

is going to go straight into that risotto.

I'm going to give them a little chop to the side whilst you keep stirring.

The ratio of stock to rice in a risotto is about 4-1.

So for 200g of rice, add around 800ml of stock.

You want to turn the heat up just a little bit because you've added something cold to the pan.

So you're constantly playing with the heat.

Constantly adjusting temperature.

In goes the porcini mushrooms,

together with some diced fresh mushrooms.

Put in two teaspoons of mascarpone cheese.

That's not a teaspoon, mate!

Tell you what, look...

In my world, that's a teaspoon!

Oh, gosh! That is a lot!

I need you to grate me a load of Parmesan cheese,

at least down to about there, half way.

Now, parmesan cheese is really important.

High in salt, high in acid.

That's going to help cut through all of the richness already in that pan.

Pop in some chives for a light garlic and onion taste.

I tell you what, this is going to be the best risotto you've had.

Brilliant!

OK, there we go.

Look at that! That looks amazing!

That's the difference between the two

and I'll be honest with you, it's just not as rich, it's not as loved.

Come on, let's have a little try.

Tom, that's delicious. Absolutely delicious.

-Happy?

-Mm. Fabulous.

If you need help with a dish that always goes wrong

then share your Kitchen Fail on social media using #BBCKitchenFails.

I'll pick a few and I'll tell you how to put it right.

True or false? Whole milk contains more calcium than skimmed milk?

The answer is false.

Since the fat portion of whole milk does not contain calcium,

you can lose the fat without losing any calcium.

Look around the supermarket shelves

and you'll see loads of own label items.

There's an alternative for just about every big brand out there.

Supermarkets offer a different range of their own brand

products at different price points - basic, standard and premium.

But when is it worth spending extra on premium

and when can we get away with a money-saving basic?

I'm teaming up with experts at Edinburgh's Queen Margaret University.

We're going to pull apart the ingredients in a fridge favourite -

mayonnaise.

The price of mayonnaise ranges between 40 pence for basic

to £3.49 for premium.

So why the huge price difference and what are we actually paying for?

Nutritionist Dr Carrie Ruxton has the answers.

I'm flabbergasted about how many ingredients there are.

-There's a lot.

-I've never made home-made mayonnaise,

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

Definitely not, no. If you're going to make it at home,

you only need four ingredients - egg yolk, vinegar, oil and lemon juice

and that is it.

I mean, some of these are ten, ten-plus ingredients.

Well, the biggest difference really is the budget ingredients,

the first one is water,

and then you go to the standard and the premium

and the first one is oil.

So budget mayo's got a lot of water in it but how do you turn

that into something that's thick and has the texture of mayonnaise?

It's that white powder right in front of you there.

That's modified maize starch - and it's basically corn starch

that's been chemically altered to turn it into a product

that creates this smooth consistency when you mix water together

with other ingredients

and keep it like that right across the shelf life.

The trick manufacturers have pulled off is using a cheap ingredient

like water as a substitute for the more expensive oil.

But this has an unexpected benefit.

Because there's less oil in this product compared with

the premium and standard, you're going to end up with less calories,

and what the figures look like

is around 280 calories per 100g for budget

right up to around 700 per 100g for standard and premium.

The budget mayo doesn't just save us money, it also saves us calories.

But do the cheaper ingredients affect the taste?

To find out, we have a panel of taste testers.

First, what do they buy?

Let's have a show of hands for basic mayonnaise,

who would buy that?

Standard? So you three standard. Why's that, Beth?

I've tried the budget ones before and they've not been very good

so I've upped it to the standard.

I'm guessing, Colin, you're more premium. Why premium?

I suppose it tastes better.

But does it?

That's what we're about to find out.

In a blind taste test, they'll score 10 different mayonnaise samples

ranging from budget and standard to premium.

Dr Laura Wyness has the results.

The budget actually scored highest, it scored 5.2 out of 9,

followed closely by the standard, scoring 5.0,

and then the premium was 4.1.

Surprisingly, when it comes to taste, budget came top

followed by standard with premium in last place.

Now what I find really fascinating is the premium

is only around half the amount of the budget,

so this is, in fact around about ten times

the cost of the budget mayonnaise.

How does that make you feel, Colin?

I think I might try the budget.

So we've found that budget mayo can save us money and calories.

And if it's taste that matters to you,

then standard and budget are pretty similar.

MUSIC: Can't Get Enough Of Your Love, Babe by Barry White

We'll go to great lengths to capture someone's heart.

From cheesy pickup lines to extravagant romantic gestures.

But there's another weapon in the arsenal of love - food.

The idea that there are certain foods

and drinks that have aphrodisiac properties goes back thousands

of years, but just because an idea is ancient, doesn't mean it's true.

So are there any aphrodisiacs

which have been scientifically proven to be effective?

What do people think works?

Ginger!

Ginger, cocktail with ginger is the best thing ever for an aphrodisiac.

Possibly champagne and oysters might work.

Well, I would say caviar.

Well, it's chocolate!

Chocolate gets something going.

There's no shortage of suggestions but where's the evidence?

Here's a man who should know.

My date for the evening,

physiologist Dr Harry Witchel from the University of Sussex.

-Well, Harry, this is delightful. Shall I open the Prosecco?

-Please!

That's very kind of you.

What exactly is an aphrodisiac?

An aphrodisiac is anything that contributes to performance

in a sexual way, that gets the whole process started.

Unfortunately, there's no scientific evidence that champagne,

strawberries or oysters have any aphrodisiac properties.

So are there any foods or drinks that can increase desire

and excite us?

Here's one I got from the shop, which is ginseng.

Many claims have been made for it,

but it is used quite regularly as an aphrodisiac.

So have there been any trials to actually see whether it does perform?

There are a few trials that suggest that in certain dosages,

it will improve sexual performance.

So is there any other herbal aphrodisiacs out there?

Today, I've brought for you ginkgo.

Thousands of years old,

it loosens vessels, so people have claimed.

So if it may be having an effect on blood vessels

and opening them up, then it seems reasonable to suggest

that it might have a Viagra-like effect.

You could make that argument.

Harry and I are keen to see if supplements do start hearts racing.

Four volunteers - Amanda, Paul, Emily and Hugo,

have agreed to take part in an experiment.

We're going to set them up on a blind date with two models -

Luciana and Daniel.

You hold that there...

Harry's looking for changes to our volunteers' heart rates.

It's not the most obvious...

Both before and after taking the supplements.

First up is Amanda.

She hasn't taken anything yet.

Let's see how her heart rate responds to model Daniel.

Her heart rate has just gone up massively!

96!

Will Emily's first impression be as positive?

-Where are you from?

-Guess.

-Croatia?

-Russia.

-Really?

It's gone up a tiny bit, like two beats per minute.

Hello.

Time to test out Hugo and Paul with model Luciana.

How are you doing?

Again, the men haven't taken any supplements yet.

-I like your hair.

-Thank you very much!

Paul seems to like the attention of Luciana.

As does Hugo.

His heart rate's gone up to 120!

That's for real!

Look at this, tick, tick, tick!

Without taking anything, both men's heart rates have shot up.

Now Harry gives our volunteers the supplements.

Amanda and Hugo are given ginseng.

While Paul and Emily are taking ginkgo.

-Do you like going to the theatre?

-I do like going to the theatre.

120 for the heart rate.

-Great dress, nice hair.

-Thank you!

-I do palm reading.

-You do?

-No.

Harry has been recording our volunteers' heart rates throughout the experiment.

First, the results from before they took the supplements.

What we saw was that the men really responded!

LAUGHTER

So Hugo went from about 82 to a heartrate of about 125,

and Paul, he ended up in the region of about 132,

so well done, you!

The women responded to Daniel in a more subtle way.

Amanda's heart rate rose from 60 to 72

while Emily's only went up by two beats per minute.

Now we're going to look at how their heart rates responded

after they took the supplements.

What happened after the ginseng and the ginkgo?

I would say that we didn't see anything really obvious

with the men, simply because they may have maxed out.

There could even be a topping out, a ceiling effect.

The increase in the men's heart rates was about the same

after they'd taken the supplements as before.

However, it was a different story for the women.

Emily, on her first go, she was at 80.

Whereas we recorded something along the lines of 107 the second time.

The results are different so clearly, internally,

there was stuff going on that I didn't know about.

The first time I marked you as a six. (Sorry).

But the second time I marked you as an eight.

So there was definitely a change.

We also see that Amanda had an improved response,

which leads us to the question as to whether you thought there was any difference.

I felt like the second one was better as well.

Mostly because I felt more comfortable, like Emily said.

Clearly the gingko did some work.

It's hard to say if the ginseng and ginkgo had any effect

on the men as they had such a strong response

even before they'd taken any supplements,

but both substances appeared to have a measurable effect on the women.

Their heart rates rose

and they found Daniel even more attractive.

It's a small experiment so we can't draw firm conclusions,

but from Harry's results, it seems there are some things

that could claim to be aphrodisiacs after all.

From food that makes our hearts flutter

to food that can't be rushed.

I've got the secrets that can transform your cooking.

In a professional kitchen, getting food consistently tasting great

relies on tips and techniques that never fail.

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

that are easy to do but incredibly effective.

From street food to top-end restaurants,

professional chefs have a clever technique for turning

cheap cuts of meat into something special.

Slow cooking breaks down the tough proteins in meat

releasing bags of flavour.

Now, slow cooking is the perfect way of tenderising

those cheaper cuts of meat -

shoulder of lamb, shin of beef, or in this case, a shoulder of pork.

And you need to slow cook cuts of meat like this

because they're working muscles.

That shoulder of pork spends all day wandering around.

That cooking process needs to break down the sinew and the muscle.

Now, I'm going to do a version of pulled pork here.

Loads of flavour, loads of things going on.

In a bowl, put sugar, salt, dried thyme, toasted cumin seeds,

some cracked black pepper, dried sage and three star anise,

which have been toasted and then ground up.

Then mix it all together,

pour it on and then massage it into the muscle meat of this pork.

Straight away, that salt and sugar starts to work its magic

and it draws moisture from the pork

and then that flavour begins to work its way into that meat.

This is the key to this technique,

because as the water is drawn out of the meat,

it's replaced by all those spices.

Now we're going to leave this pork in the fridge overnight.

So this is one that has been marinading for 12 hours.

That pork has been able to take on a load of flavour

that's come from that dry rub mix.

I'm just going to pop it into a tray,

and then I'm going to cover it with chicken stock.

Adding stock not only provides flavour

but crucially the liquid will steam the meat,

and that's what we need to happen.

OK, and that's it.

Tin foil nice and tightly on,

just going to stick this pork in the oven, 150 degrees centigrade,

and we'll come back to it in about five hours' time.

You could use a slow cooker

but in a professional kitchen, we just do it in the oven.

Oh, it smells incredible.

Slow cooked, and literally with two forks,

I'm just going to pull it all apart,

hence why it's called pulled pork.

I'm going to stick this in a bun

with some lovely home-made coleslaw.

Lid on, look at that.

You have to do this at home, people.

You can find this trade secret and more on the website.

Go to...

Next time - can chillies help us lose weight?

We just want to put about four level teaspoons in...

That's going to be extremely hot!

Sean puts food labelling to the test.

I think you'd need a PhD in maths to do all the calculations.

And Tom reveals the secrets to a perfect steak.

It's a little bit beige.

I mean, beige is nice if it's a car in the 1970s.