0:00:02 > 0:00:04Welcome to Bang Goes The Theory, bringing you the science
0:00:04 > 0:00:06behind the headlines and tackling the issues
0:00:06 > 0:00:08that impact all of our lives.
0:00:08 > 0:00:11The discovery of horse meat in beef products earlier this year
0:00:11 > 0:00:14has prompted some serious investigations.
0:00:14 > 0:00:17It's also been a veritable feast for the headline-writers.
0:00:17 > 0:00:19On the whole, it's a story of deceit.
0:00:19 > 0:00:21Someone somewhere in the supply chain
0:00:21 > 0:00:24passing food off for something that it isn't.
0:00:24 > 0:00:28And it has brought up a lot of questions about the food industry,
0:00:28 > 0:00:30making us all think more about what we're eating
0:00:30 > 0:00:33and where it comes from. But for answers,
0:00:33 > 0:00:36you need to look at the facts, and that's where the science comes in.
0:00:36 > 0:00:39So tonight we're lifting the lid on food technology.
0:00:41 > 0:00:44Coming up, I investigate the invisible tricks
0:00:44 > 0:00:46used to keep our food fresh.
0:00:48 > 0:00:49Whoa! Look at that!
0:00:51 > 0:00:54Maggie finds out how science can add gourmet flavour
0:00:54 > 0:00:55to bland food.
0:00:55 > 0:00:59It's really got a nasty aroma, but it's required.
0:00:59 > 0:01:03You need to have it there to give you that nice fried steak aroma.
0:01:03 > 0:01:08And Liz discovers the weird things added to our food to keep it looking good.
0:01:08 > 0:01:12And what you get is this almost soapy material.
0:01:12 > 0:01:14And what this is designed to do
0:01:14 > 0:01:16is kind of the same thing that the egg does.
0:01:16 > 0:01:19That's Bang Goes The Theory on processed food.
0:01:22 > 0:01:26Recent news reports have really made us question what's in our food.
0:01:26 > 0:01:28I'm not that concerned about eating horse,
0:01:28 > 0:01:32but I am concerned about the labelling issue. So if you buy something that says 100% beef,
0:01:32 > 0:01:35that's what you expect it to be. So there's definitely a trust issue there.
0:01:35 > 0:01:38The general public are fed up with being conned now.
0:01:38 > 0:01:41And they feel conned by the food manufacturers.
0:01:41 > 0:01:43They're making a lot of money.
0:01:43 > 0:01:47Absolutely shocked, because if they can do that to food,
0:01:47 > 0:01:51they could put other things into food that we're not aware of.
0:01:52 > 0:01:55When it came to exposing the horse meat fraud,
0:01:55 > 0:01:59the forensic weapon in the limelight was DNA analysis.
0:01:59 > 0:02:00Without this technology,
0:02:00 > 0:02:04identifying minced horse meat in food would have been impossible.
0:02:05 > 0:02:08But the horse meat scandal is small
0:02:08 > 0:02:10in comparison to what goes on with fish.
0:02:10 > 0:02:14The Food Standards Agency has revealed that one in ten fish dishes
0:02:14 > 0:02:16are not quite what they seem.
0:02:16 > 0:02:19So I'm making my own mystery fish pie
0:02:19 > 0:02:21to find out how they're investigated.
0:02:23 > 0:02:26Quality fish simply isn't cheap any more.
0:02:26 > 0:02:29And food manufacturers have been substituting
0:02:29 > 0:02:31fish like prime North Atlantic cod, for example,
0:02:31 > 0:02:34in ready meals like fish pies
0:02:34 > 0:02:35for cheaper alternatives,
0:02:35 > 0:02:38and that's where DNA analysis comes in.
0:02:38 > 0:02:40DNA testing for fish is so advanced
0:02:40 > 0:02:44that it can identify over 1,000 different species.
0:02:44 > 0:02:47So, in theory, it should be virtually impossible
0:02:47 > 0:02:50for a rogue species to make it into a dish.
0:02:50 > 0:02:52But is it?
0:02:52 > 0:02:56OK, so in this pie are several different types of fish,
0:02:56 > 0:02:57all bought on the high street,
0:02:57 > 0:03:02one of which is a rogue species that's often substituted for cod.
0:03:03 > 0:03:06The question is, will DNA analysis
0:03:06 > 0:03:09be able to identify all six species correctly?
0:03:09 > 0:03:13We've sent our pie to one of the top fish genetics labs in the country
0:03:13 > 0:03:15at Bangor University.
0:03:15 > 0:03:20OK, so, Mark, here we have the mystery fish pie.
0:03:20 > 0:03:23The first stage of their analysis
0:03:23 > 0:03:26is to extract and clean the fish meat.
0:03:26 > 0:03:29The fish DNA is extracted using ethanol.
0:03:29 > 0:03:33Then a specific gene that's present in all fish
0:03:33 > 0:03:37is pinpointed, and using PCR, a sort of molecular photocopier,
0:03:37 > 0:03:42millions of copies of this genetic bar code are made.
0:03:42 > 0:03:47By reading that bar code, they can identify the exact species of fish.
0:03:50 > 0:03:51Maggie has gone to Bangor
0:03:51 > 0:03:54to get the results from Professor Gary Carvalho,
0:03:54 > 0:03:55who runs the lab.
0:03:59 > 0:04:03I can't wait to find out whether you've identified the fish in our pie.
0:04:03 > 0:04:05Those mystery fish. Neither can I!
0:04:05 > 0:04:06I'm even more anxious than you are.
0:04:06 > 0:04:10OK, well, based on what we could see in terms of the colour
0:04:10 > 0:04:12and the texture of the chunks in the fish pie,
0:04:12 > 0:04:16we actually think we have six different species of fish.
0:04:16 > 0:04:19And that gets the first big tick, because, as you see on our fish chart,
0:04:19 > 0:04:21there are six species.
0:04:21 > 0:04:23But have you correctly identified them?
0:04:23 > 0:04:26When we get the data back, we have a trace of the sequences.
0:04:26 > 0:04:30- So that's one fish there?- This is the trace from one fish.
0:04:30 > 0:04:34Essentially, the DNA is an alphabet of just basically four letters
0:04:34 > 0:04:36and it's the combination and the order of those letters
0:04:36 > 0:04:39that collectively will tell us specific species.
0:04:39 > 0:04:43And over a third of fish species have now been bar-coded
0:04:43 > 0:04:45and they are in the reference database.
0:04:45 > 0:04:49So it means we can take our mystery unknown sequences,
0:04:49 > 0:04:51drop them into the database
0:04:51 > 0:04:53and then search for a match.
0:04:53 > 0:04:56So what it is telling us, with a very high level of certainty,
0:04:56 > 0:05:00it's telling us that the first piece of tissue that we extracted DNA from
0:05:00 > 0:05:02belongs to Atlantic salmon.
0:05:04 > 0:05:06- Ta-da!- We have an Atlantic salmon.
0:05:06 > 0:05:08Very good! Very good.
0:05:08 > 0:05:09The other fish that we've identified
0:05:09 > 0:05:11are trout...
0:05:11 > 0:05:12Excellent.
0:05:12 > 0:05:14And the third fish
0:05:14 > 0:05:16we thought was cod.
0:05:17 > 0:05:20- Cod.- And the fourth fish
0:05:20 > 0:05:21was haddock.
0:05:21 > 0:05:24- OK.- It is a very tense game.
0:05:24 > 0:05:27There's no massive prize, sadly, at the end of this!
0:05:27 > 0:05:28I feel as if there should be.
0:05:28 > 0:05:30Two to go.
0:05:30 > 0:05:31OK.
0:05:31 > 0:05:34Now, with the other two, we had difficulties in terms of
0:05:34 > 0:05:35- the quality of the sequence.- OK.
0:05:35 > 0:05:39So, one of them we actually thought was not a very good-quality sequence.
0:05:39 > 0:05:43Visually, when we took it from the pie,
0:05:43 > 0:05:45it looked to us like it could be catfish.
0:05:45 > 0:05:48Vietnamese catfish, otherwise known as river cobbler.
0:05:48 > 0:05:52But we had it sequenced alongside all of our other samples,
0:05:52 > 0:05:55and it came back as a bacterium.
0:05:55 > 0:05:59So it can actually, of course, indicate poorly stored fish.
0:05:59 > 0:06:03When we think about Vietnam, it's a long distance away,
0:06:03 > 0:06:04and the likelihood is of course
0:06:04 > 0:06:07that for part of that, or periods of that,
0:06:07 > 0:06:10the fish may have been stored above freezing for quite some time.
0:06:10 > 0:06:12Well, let's just see if you're correct.
0:06:12 > 0:06:15And it is indeed river cobbler.
0:06:15 > 0:06:19And of course, this was at the heart of the scandal in fish and chip shops, wasn't it?
0:06:19 > 0:06:20Yes, indeed.
0:06:20 > 0:06:23River cobbler has been a major culprit actually
0:06:23 > 0:06:25of substitution across the world.
0:06:25 > 0:06:27Once it's been stored for a period of time,
0:06:27 > 0:06:30the white flesh can look something like cod or...
0:06:30 > 0:06:33And, of course, it is I think quite readily substituted.
0:06:33 > 0:06:36And in our red herring pie,
0:06:36 > 0:06:39this was the fish that we wondered whether or not you would spot.
0:06:39 > 0:06:42It was quite evident to us, or very likely to be a catfish,
0:06:42 > 0:06:44so something we could readily recognise.
0:06:46 > 0:06:50The identity of the last species wasn't clear from the first analysis,
0:06:50 > 0:06:53but a routine second test did confirm the result.
0:06:56 > 0:06:59The quality of the sequence is not up to our usual standard,
0:06:59 > 0:07:01but we do have pretty high certainty
0:07:01 > 0:07:03that it was monkfish,
0:07:03 > 0:07:06based on re-sequencing it more than once.
0:07:06 > 0:07:09A re-test also confirmed the river cobbler,
0:07:09 > 0:07:12complete with bacterial contamination,
0:07:12 > 0:07:16giving Dr Carvalho an impressive six out of six.
0:07:17 > 0:07:21We see all these fish on the board here. They're clearly identifiable, easy to distinguish,
0:07:21 > 0:07:24but once fish have been processed and filleted,
0:07:24 > 0:07:26often prepared in a variety of ways,
0:07:26 > 0:07:28it becomes increasingly difficult
0:07:28 > 0:07:32to be absolutely certain that what is on the label is what is inside the packet.
0:07:35 > 0:07:38Technology like this doesn't just benefit consumers.
0:07:38 > 0:07:40It's also helping to tackle illegal fishing
0:07:40 > 0:07:43and protect vulnerable fish stocks,
0:07:43 > 0:07:46because Professor Carvalho has pioneered a system
0:07:46 > 0:07:50that can even pinpoint where certain species were caught.
0:07:51 > 0:07:54From this year, all fish and fish products
0:07:54 > 0:07:55which is eaten within the EU
0:07:55 > 0:07:58will have to be labelled not only with the species,
0:07:58 > 0:08:00but whether it's wild or farmed,
0:08:00 > 0:08:03and it will have to state exactly where it's been caught.
0:08:03 > 0:08:07And with these advances in fish forensics,
0:08:07 > 0:08:08it's going to get harder and harder
0:08:08 > 0:08:11for the fraudsters to slip through the net.
0:08:17 > 0:08:19Thank you very much. Cheers.
0:08:19 > 0:08:22So, that's good news for fish eaters,
0:08:22 > 0:08:25but you do have to wonder why this technology wasn't used
0:08:25 > 0:08:27to avoid the horse meat scandal.
0:08:27 > 0:08:31But the thing is, fish testing is very different to meat testing.
0:08:31 > 0:08:34In meat testing, you're looking specifically for cross-contamination
0:08:34 > 0:08:37with other farmed meats, so you're looking for the DNA of lamb and beef
0:08:37 > 0:08:39and pork and poultry,
0:08:39 > 0:08:42but not for the DNA of horse.
0:08:42 > 0:08:44It was only after a tip-off that they went looking for it,
0:08:44 > 0:08:46and unfortunately found it.
0:08:50 > 0:08:54But food fakery is only one of the things that worries consumers.
0:08:56 > 0:08:59Just look at the produce, and if I think it looks good, I'll buy it.
0:08:59 > 0:09:03Spraying your fruit with this or that to make it keep its shine and everything else,
0:09:03 > 0:09:06so, yeah, I'm sure there's all sorts of unsavoury practices going on.
0:09:06 > 0:09:08One of the tricks of the trade
0:09:08 > 0:09:11is to package food in strange atmospheres.
0:09:11 > 0:09:13So what's that all about?
0:09:14 > 0:09:18Meat is actually packaged quite often in an atmosphere very rich in oxygen -
0:09:18 > 0:09:21far more oxygen than we're used to breathing.
0:09:25 > 0:09:26Blow this out.
0:09:30 > 0:09:33It leaps into flame very easily.
0:09:33 > 0:09:34Whoa! Look at that!
0:09:34 > 0:09:37Now, the reason for this is for cosmetics.
0:09:37 > 0:09:41Just as blood turns a brighter red with oxygen,
0:09:41 > 0:09:42so does muscle.
0:09:42 > 0:09:45And so, by flooding it with oxygen,
0:09:45 > 0:09:46the kind of muscle in there
0:09:46 > 0:09:49gets to look much redder than it would normally.
0:09:49 > 0:09:52And we think that's the one to buy.
0:09:55 > 0:09:58But pre-packaged salads could be the total opposite.
0:09:58 > 0:10:01They're packed in atmospheres with very little oxygen.
0:10:01 > 0:10:03I'll show you what I mean.
0:10:03 > 0:10:04Light this...
0:10:04 > 0:10:07and I plunge it into a little...
0:10:07 > 0:10:09basket of salad...
0:10:11 > 0:10:13It will not stay alight.
0:10:15 > 0:10:18And that's because there's no oxygen in there, really.
0:10:18 > 0:10:22And so the things that would normally cause the food to rot and decay
0:10:22 > 0:10:25can't thrive, so the food stays fresh a lot longer.
0:10:27 > 0:10:31We all want to buy fruit and veg at the peak of perfection.
0:10:31 > 0:10:34But there's a fine balance between ripe and rotten.
0:10:34 > 0:10:38And getting that right is all about another gas -
0:10:38 > 0:10:39ethylene.
0:10:39 > 0:10:43This is the same gas that plants use to make flowers open,
0:10:43 > 0:10:46leaves change colour and drop off in the autumn.
0:10:50 > 0:10:53Because ethylene's regarded as dangerous,
0:10:53 > 0:10:54it's difficult to get.
0:10:54 > 0:10:56So I'm going to make my own,
0:10:56 > 0:10:58starting with ethanol.
0:11:00 > 0:11:03I need to heat the ethanol in order to vaporise it
0:11:03 > 0:11:07and break it down into water and ethylene gas.
0:11:09 > 0:11:12What I've collected here should now be pure ethylene gas.
0:11:16 > 0:11:18It certainly smells pretty fruity.
0:11:18 > 0:11:21And it's phenomenally flammable.
0:11:23 > 0:11:27It's harmless to humans, and to fruit, it's a ripening hormone.
0:11:28 > 0:11:31I'm adding a quick blast of ethylene here,
0:11:31 > 0:11:33just like they do to kick-start ripening
0:11:33 > 0:11:35before bananas are delivered to the shops.
0:11:37 > 0:11:41From then on, it produces its own and continues the process.
0:11:42 > 0:11:44So the timing is critical,
0:11:44 > 0:11:47or your banana will end up too ripe too soon.
0:11:54 > 0:11:56For fruit distributors like this one,
0:11:56 > 0:11:59getting ethylene levels right is crucial.
0:12:00 > 0:12:03Working with it as opposed to railing against it
0:12:03 > 0:12:06has enabled suppliers to time their fruit and veg deliveries
0:12:06 > 0:12:08to near perfection.
0:12:10 > 0:12:14Apples are relatively easy to store.
0:12:14 > 0:12:16Cold storage does most of the job,
0:12:16 > 0:12:19but they're kept separately so their ethylene production
0:12:19 > 0:12:21doesn't affect more sensitive fruits.
0:12:26 > 0:12:28But pears we want to be much juicier.
0:12:28 > 0:12:31They are taken right to the brink of ripeness before packing,
0:12:31 > 0:12:34but then held there as long as possible
0:12:34 > 0:12:36by these little white patches -
0:12:36 > 0:12:37ethylene absorbers -
0:12:37 > 0:12:40which mop up the gas inside the packet.
0:12:40 > 0:12:43So, when I buy them, should I keep them in the packet that you delivered them,
0:12:43 > 0:12:47with their little ethylene absorption patch, and then they'll last longer?
0:12:47 > 0:12:49That's exactly what you should do, really.
0:12:49 > 0:12:52Just before you want to eat them, about an hour or so,
0:12:52 > 0:12:55take them out of the cold fridge, put them on the side.
0:12:55 > 0:12:57The temperature changes to room temperature,
0:12:57 > 0:12:58and you'll get an enjoyable experience.
0:13:02 > 0:13:05For the perfect avocado experience,
0:13:05 > 0:13:08the whole process gets much more complicated.
0:13:10 > 0:13:14This machine actually checks out every single avocado.
0:13:14 > 0:13:16They're kind of tapped and listened to
0:13:16 > 0:13:19to find out what they're like inside,
0:13:19 > 0:13:23then they're photographed from many angles to find out what they're like on the outside.
0:13:23 > 0:13:25And then, from that, a computer deduces
0:13:25 > 0:13:28exactly what state each one's in
0:13:28 > 0:13:30and whether it's supposed to be eaten in two days
0:13:30 > 0:13:32or whether it'll be perfect in a week or ten days.
0:13:32 > 0:13:36Avocados don't even ripen at all until they're picked.
0:13:36 > 0:13:39But from then on, it's a tricky balancing act
0:13:39 > 0:13:43to store them en masse, but also ensure they all get ready together.
0:13:44 > 0:13:47It's a combination of temperature control
0:13:47 > 0:13:50and these large ethylene absorption pads.
0:13:50 > 0:13:53And basically, what this is doing is absorbing the ethylene
0:13:53 > 0:13:56from the ones that are ripening quicker than the others.
0:13:56 > 0:13:59So it's basically shutting them ones down
0:13:59 > 0:14:01in terms of their speed of maturity,
0:14:01 > 0:14:05allowing the ones that are less mature to catch up, and so hopefully,
0:14:05 > 0:14:07you end up with a much more even sample.
0:14:09 > 0:14:12Visiting this packing factory has made me realise
0:14:12 > 0:14:15that different kinds of fruit are all speaking the same language.
0:14:15 > 0:14:18And it's called ethylene.
0:14:18 > 0:14:20And these avocados have to be kept separate
0:14:20 > 0:14:24from the apples and pears, to stop them talking to each other,
0:14:24 > 0:14:25to stop one releasing ethylene
0:14:25 > 0:14:29and telling the others to start ripening and start changing rapidly.
0:14:29 > 0:14:31And these things here...
0:14:31 > 0:14:33they're almost like kind of mufflers
0:14:33 > 0:14:34that absorb the ethylene
0:14:34 > 0:14:37to stop them communicating with each other.
0:14:38 > 0:14:41It's really about understanding the biology of what we eat
0:14:41 > 0:14:42in order to keep it fresher for longer,
0:14:42 > 0:14:46so we can get more out of it and hopefully produce less waste.
0:14:47 > 0:14:49Which has to be a good thing.
0:14:51 > 0:14:53Still to come tonight,
0:14:53 > 0:14:57Maggie discovers how scientists can fool us with flavours.
0:14:57 > 0:14:59But first, I'm taking a look at the additives
0:14:59 > 0:15:02that seem to be in so much of our food.
0:15:04 > 0:15:07If you take a look at the list of ingredients in a lot of the stuff that you buy,
0:15:07 > 0:15:10chances are there's a whole bunch of things
0:15:10 > 0:15:11you've probably never even heard of.
0:15:11 > 0:15:13So what are they,
0:15:13 > 0:15:16and why do they feature so heavily in foods like these?
0:15:16 > 0:15:20- Can I rummage around and have a look at what you might have?- Yes.
0:15:20 > 0:15:21Let me see these. Listen to this.
0:15:21 > 0:15:25"Flavourings, colours, E104, E122, E110..."
0:15:25 > 0:15:28- Any idea what they are and what they're for?- No.
0:15:28 > 0:15:31When you read a label, you need to be in the pharmacy industry
0:15:31 > 0:15:34to understand all the chemicals and other bits and pieces.
0:15:34 > 0:15:36"E471, E920,
0:15:36 > 0:15:40"emulsifiers and calcium propionate." Any ideas?
0:15:40 > 0:15:42No.
0:15:42 > 0:15:44- Dextrose - do you know what dextrose is?- No.
0:15:44 > 0:15:48- Do you know what "stabiliser E451" is?- No.
0:15:48 > 0:15:52Why would you want to put stabiliser in chicken? What would it be for? Do you know?
0:15:52 > 0:15:55Er...again, I haven't the faintest idea.
0:15:56 > 0:16:00The truth is, additives go hand-in-hand with processed food,
0:16:00 > 0:16:04which is pretty much everything that isn't a raw ingredient.
0:16:06 > 0:16:08A really good example of how additives
0:16:08 > 0:16:11can be fairly obvious in foods is salad dressings.
0:16:11 > 0:16:13Now, first up, if I make my own at home,
0:16:13 > 0:16:16all I'm going to put in is a bit of olive oil
0:16:16 > 0:16:19and vinegar.
0:16:19 > 0:16:23And then I always bung in a bit of mustard.
0:16:23 > 0:16:25And then just give it a good stir.
0:16:25 > 0:16:27And that does the job.
0:16:27 > 0:16:29No additives needed.
0:16:29 > 0:16:32Now, oil and vinegar
0:16:32 > 0:16:34don't mix,
0:16:34 > 0:16:37but the mustard in my dressing... A - tastes really good,
0:16:37 > 0:16:39but B - it acts as an emulsifier.
0:16:39 > 0:16:42And what means is there's a chemical in the mustard
0:16:42 > 0:16:47that bridges the gap between oil molecules and vinegar molecules
0:16:47 > 0:16:49that essentially repel each other
0:16:49 > 0:16:51and essentially makes my dressing into an emulsion.
0:16:51 > 0:16:53But that doesn't last very long.
0:16:53 > 0:16:56Now, as my salad dressing settles,
0:16:56 > 0:16:58you can see all the different components -
0:16:58 > 0:17:00the oil and the vinegar separating
0:17:00 > 0:17:02and also all the mustard seeds have settled
0:17:02 > 0:17:04to the bottom.
0:17:06 > 0:17:10But if I show you an equivalent salad dressing
0:17:10 > 0:17:11that comes from a shop...
0:17:11 > 0:17:13There's no separation whatsoever
0:17:13 > 0:17:16and all the seeds are suspended throughout.
0:17:16 > 0:17:18It looks very different.
0:17:18 > 0:17:24But I need just one secret ingredient to get my DIY dressing bottle-ready.
0:17:26 > 0:17:31Now, this is E415, or xanthan gum.
0:17:31 > 0:17:36It's a very popular additive - it's used in hundreds of salad dressings and sauces.
0:17:36 > 0:17:39And it comes from this little bacteria,
0:17:39 > 0:17:41Xanthomonas campestris,
0:17:41 > 0:17:44and it's what causes the black spots on broccoli and cabbage.
0:17:44 > 0:17:47And it uses this gum-like substance
0:17:47 > 0:17:50that it secretes to attach to the leaves of the vegetables.
0:17:50 > 0:17:52But when that gum is dried out,
0:17:52 > 0:17:53it looks like this.
0:17:53 > 0:17:55And if I add
0:17:55 > 0:18:00a little bit to my dressing and stir...
0:18:00 > 0:18:02Look at that already.
0:18:02 > 0:18:05I can notice a bit of a difference.
0:18:05 > 0:18:09The gum further emulsifies the dressing,
0:18:09 > 0:18:12but also surrounds the molecules of oil and vinegar,
0:18:12 > 0:18:17stabilising the mixture so that the oil and vinegar can't separate back out.
0:18:17 > 0:18:20But xanthan is also a thickener.
0:18:20 > 0:18:23It's also made my dressing a lot more viscous
0:18:23 > 0:18:25and that means that all the mustard seeds
0:18:25 > 0:18:28are now sort of permanently suspended
0:18:28 > 0:18:31in my dressing, and suddenly...
0:18:31 > 0:18:34these two don't look that dissimilar any more.
0:18:36 > 0:18:40Because it's so thick, I can even water it down.
0:18:41 > 0:18:44Which not only makes it cheaper to produce,
0:18:44 > 0:18:48it also gives you a fraction of the calories per teaspoon.
0:18:51 > 0:18:55Xanthan is just one of hundreds of additives used in our food.
0:18:58 > 0:19:00Chemistry professor Andrea Sella
0:19:00 > 0:19:01is going to show me some
0:19:01 > 0:19:03of the most commonly used additives
0:19:03 > 0:19:04in mass-produced food
0:19:04 > 0:19:06like this Victoria sponge cake.
0:19:08 > 0:19:10OK, so what are the challenges
0:19:10 > 0:19:14you have to face when you're making cakes on a mass scale?
0:19:14 > 0:19:17One of the things you're going to have to worry about is shelf life.
0:19:17 > 0:19:19Now, we know that if we leave a cake lying around,
0:19:19 > 0:19:20it's going to dry out.
0:19:20 > 0:19:24So, for example, there are things called humectants.
0:19:24 > 0:19:26These are really edible moisturisers.
0:19:26 > 0:19:29A good example of this would be glucose syrup.
0:19:29 > 0:19:32Humectants like glucose and glycerin
0:19:32 > 0:19:36keep the cake moist, but also stop mould growing
0:19:36 > 0:19:37and extend the shelf life.
0:19:39 > 0:19:42But mass-produced foods also need to be consistent.
0:19:44 > 0:19:46If you think about when you bake at home,
0:19:46 > 0:19:50you know, one cake will always be very slightly different from the next.
0:19:50 > 0:19:52And a big producer cannot afford that.
0:19:52 > 0:19:55Every single cake must come out completely identical.
0:19:55 > 0:19:58So what they really need is control.
0:19:58 > 0:20:01And this is where emulsifiers come in.
0:20:01 > 0:20:04What you get is this slightly sort of...
0:20:04 > 0:20:07gloppy, soapy material.
0:20:07 > 0:20:09It feels a bit like Vaseline as well.
0:20:09 > 0:20:11It certainly feels odd.
0:20:11 > 0:20:12And what this is designed to do
0:20:12 > 0:20:15is kind of the same thing as the egg does
0:20:15 > 0:20:16when you bake a cake,
0:20:16 > 0:20:22and that is to control the bubbles within...within your cake.
0:20:22 > 0:20:26- But much more than the eggs do?- And it provides much finer control,
0:20:26 > 0:20:28much more careful control.
0:20:28 > 0:20:31In fact, what it really does is to ensure
0:20:31 > 0:20:36that we will get a consistent structure to the bubbles inside our cake.
0:20:40 > 0:20:44So, additives definitely serve a very useful purpose
0:20:44 > 0:20:47in the food industry, and when it comes to safety,
0:20:47 > 0:20:50of course questions will be raised every now and again.
0:20:50 > 0:20:55But every additive that features in our food has been rigorously tested.
0:20:55 > 0:20:57And indeed, the "E" in every E number
0:20:57 > 0:21:01simply means that the additive has passed European safety testing.
0:21:05 > 0:21:07Thanks to the additives in processed foods,
0:21:07 > 0:21:09more often than not,
0:21:09 > 0:21:12what you're tasting isn't quite what you're eating.
0:21:14 > 0:21:16I've come to the University of Reading
0:21:16 > 0:21:21to find out how scientists manage to give plain food gourmet flavour.
0:21:23 > 0:21:27- So, Maggie, how do you like your steak?- I'm a medium rare kind of person.- Excellent.
0:21:27 > 0:21:29I'm glad to hear it, because I like...
0:21:29 > 0:21:33Today Dr Jane Parker is cooking up a prime pan-fried steak
0:21:33 > 0:21:36to show me what makes it so deliciously meaty.
0:21:36 > 0:21:39If you are a meat eater, there is nothing like that moment
0:21:39 > 0:21:42when the steak goes in the pan and then all...
0:21:42 > 0:21:45You start to get aromas coming up already. It doesn't take very long
0:21:45 > 0:21:47- till you get that aroma coming off. - Yes.
0:21:47 > 0:21:50And what's happening on the other side is it's starting to go brown.
0:21:54 > 0:21:57The basic flavour of food comes from its taste -
0:21:57 > 0:22:01bitter, sweet, sour, salty and, if it's meat, umami.
0:22:01 > 0:22:03But far more important for flavour
0:22:03 > 0:22:06is the food's aroma.
0:22:06 > 0:22:10So, yeah, you can stick your nose in and smell that aroma coming off.
0:22:10 > 0:22:13So Jane's first step is to identify
0:22:13 > 0:22:16the signature components of gourmet steak aroma.
0:22:16 > 0:22:20She puts the pieces of steak into a gas chromatograph,
0:22:20 > 0:22:22which collects the aroma,
0:22:22 > 0:22:25before separating out and measuring every component,
0:22:25 > 0:22:28displaying the results on a graph.
0:22:28 > 0:22:31Each peak is a single component
0:22:31 > 0:22:36that's come from the aroma that's come off the steak.
0:22:36 > 0:22:39- Probably at least 100.- I would say a couple of hundred, easily.
0:22:39 > 0:22:43But you could go up to 600 if you looked at absolutely everything that was there.
0:22:43 > 0:22:47There's one somewhere here that is a very interesting compound.
0:22:47 > 0:22:50People describe it as rotting drains, rotting vegetables,
0:22:50 > 0:22:52rotten eggs. It's really got a nasty aroma,
0:22:52 > 0:22:55but it's required. You need to have it there
0:22:55 > 0:22:58to give you that nice fried steak aroma.
0:22:58 > 0:23:02Where do you start when you're trying to recreate something
0:23:02 > 0:23:05which can almost con our taste buds into thinking,
0:23:05 > 0:23:07"Mmm, delicious meaty flavour"?
0:23:07 > 0:23:09Well, the first thing you need to do is work out
0:23:09 > 0:23:12which of the peaks are important,
0:23:12 > 0:23:16which compounds are actually giving you the aromas that you need.
0:23:17 > 0:23:20But giving a delicious flavour to processed food
0:23:20 > 0:23:23is more complicated than just adding those aroma compounds.
0:23:23 > 0:23:25In something like a steak,
0:23:25 > 0:23:28there are specific natural chemicals which react together during cooking,
0:23:28 > 0:23:31each combination generating a different aroma.
0:23:31 > 0:23:35Those precursor chemicals build up in meat as it matures,
0:23:35 > 0:23:38producing an even stronger reaction in the pan.
0:23:38 > 0:23:40And that's what gives a quality steak
0:23:40 > 0:23:42its rich, gourmet aroma.
0:23:42 > 0:23:44It's called the Maillard reaction,
0:23:44 > 0:23:48and it gives all cooked foods their signature aroma.
0:23:48 > 0:23:51- This is a real art, isn't it? - Oh, it is.
0:23:51 > 0:23:53You need the science, you need the chemistry,
0:23:53 > 0:23:55to understand how the flavours are generated.
0:23:55 > 0:23:58But there's an awful lot of art in it as well.
0:23:58 > 0:24:03You need to have a good nose to be able to create an aroma that's convincing.
0:24:03 > 0:24:05One man who can do that
0:24:05 > 0:24:07is Dr David Baines.
0:24:07 > 0:24:10He's worked out which of the precursor chemicals in a steak
0:24:10 > 0:24:13are responsible for those signature aroma peaks.
0:24:13 > 0:24:15To reproduce that natural flavour,
0:24:15 > 0:24:18he just mixes those chemicals and cooks them.
0:24:18 > 0:24:21First, a dash of natural ribose powder.
0:24:21 > 0:24:24This is a key sugar in meat.
0:24:24 > 0:24:26Next, some cysteine.
0:24:26 > 0:24:30This is the powerhouse. This produces hydrogen sulphide.
0:24:32 > 0:24:34Then a pinch of glutamic acid,
0:24:34 > 0:24:37a natural monosodium glutamate or MSG
0:24:37 > 0:24:39and some ribonucleotides.
0:24:41 > 0:24:42The ribonucleotides
0:24:42 > 0:24:45and the glutamate are what give us...
0:24:45 > 0:24:46umami.
0:24:46 > 0:24:50- And that's the fifth...- The fifth taste, yes.
0:24:50 > 0:24:53Sweet, sour, bitter, salty, umami.
0:24:55 > 0:24:57A dollop of yeast extract adds body.
0:24:57 > 0:25:00And it won't work without the water.
0:25:00 > 0:25:03At this stage, the mixture has very little flavour,
0:25:03 > 0:25:07but that will all change after half an hour in a pressure cooker.
0:25:08 > 0:25:10Now, it may seem very artificial,
0:25:10 > 0:25:14but this lab flavour could be safer than the real thing.
0:25:14 > 0:25:16When you cook a piece of meat,
0:25:16 > 0:25:19you do get some substances formed
0:25:19 > 0:25:21that have been linked to cancer.
0:25:21 > 0:25:24They're formed from a precursor called creatine.
0:25:24 > 0:25:28I don't use creatine, so they're not going to be formed.
0:25:29 > 0:25:31As you do with a normal pressure cooker...
0:25:32 > 0:25:35Finally, it's time to check the results.
0:25:38 > 0:25:40I can smell it already.
0:25:42 > 0:25:46And here we have it. You see the colour formation's taken place.
0:25:46 > 0:25:47Ooh!
0:25:49 > 0:25:51I'm not sure whether that's pleasant or not.
0:25:51 > 0:25:55That has to be the beefiest beef I have ever smelt.
0:25:55 > 0:25:56# Gravy
0:25:56 > 0:25:59# On my mashed potatoes give me Gravy... #
0:25:59 > 0:26:01Now for the test.
0:26:01 > 0:26:03We've taken some bland, pre-sliced beef
0:26:03 > 0:26:06with none of the flavour of a prime pan-fried steak
0:26:06 > 0:26:09and we're going to see if a few drops of David's potion
0:26:09 > 0:26:11can give it a flavour makeover.
0:26:11 > 0:26:15Add gravy to each sample, but only those with a blue flag
0:26:15 > 0:26:17get gravy containing the flavouring.
0:26:21 > 0:26:24Well, they say the proof of the pudding is in the eating, so let's put it to the test.
0:26:26 > 0:26:29Excuse me. Do you have a moment to help us with a taste test?
0:26:29 > 0:26:32Our guinea pigs are students from the University of Reading.
0:26:32 > 0:26:36I asked them which tastes meatier - red or blue?
0:26:39 > 0:26:40Red, I think.
0:26:40 > 0:26:41I think blue.
0:26:41 > 0:26:43Tell me which one is the meatiest.
0:26:48 > 0:26:50- Definitely this one, the blue one. - Really?
0:26:50 > 0:26:53- The first one's more meaty. - So the first one much meatier?
0:26:53 > 0:26:55The blue one's really strong, like super-strong,
0:26:55 > 0:26:58whereas the red one's quite watery, I find. Not much taste.
0:27:00 > 0:27:0280% of the people we asked
0:27:02 > 0:27:04thought our enhanced beef was tastier.
0:27:06 > 0:27:10- The blue one.- The blue one. And how did that taste in your mouth compared to the red one?
0:27:10 > 0:27:12It's just got more flavour.
0:27:14 > 0:27:18In our experiment, we were only using flavourings to make bland meat taste meatier.
0:27:18 > 0:27:20But they can also help us in the search
0:27:20 > 0:27:23to find new sustainable sources of protein.
0:27:28 > 0:27:30Whether it's from meat grown in a test tube,
0:27:30 > 0:27:32insects
0:27:32 > 0:27:33or mycoprotein,
0:27:33 > 0:27:38lab-made flavours could transform alternative sources of protein
0:27:38 > 0:27:41into something much more pleasing to the palate.
0:27:42 > 0:27:46One thing's for sure - food technology involves a broad and fascinating range of science,
0:27:46 > 0:27:50and it is to a great extent driven by the need to keep costs down,
0:27:50 > 0:27:53reduce waste and meet customer demand.
0:27:53 > 0:27:54Absolutely. And the important thing
0:27:54 > 0:27:57is to arm yourself with as much information as possible
0:27:57 > 0:28:00so you can decide what you want to eat and what you don't.
0:28:00 > 0:28:02- We'll see you next time. Bye. - Goodbye.
0:28:02 > 0:28:06Visit bbc.co.uk for another one of my web exclusives.
0:28:06 > 0:28:09And you can follow the links to the Open University
0:28:09 > 0:28:13for more information on food importing and the global supply chain.
0:28:18 > 0:28:20Subtitles by Red Bee Media Ltd