Artificial flavours are more complex and interesting than first appears. Chris Baraniuk discovers a world of sensory trickery – and a curious myth about fake banana.

Banana flavouring. You know it well. If you close your eyes for a moment and think back to those countless pieces of confectionary or flavoured puddings, that recognisably artificial banana-like note will probably come back to you. Monotone, saccharine, and quite removed from the real, fresh bananas you eat as a snack or with lunch.

Artificial flavours like these are often criticised as unnatural. However, some artificial flavourings are significantly closer to ‘natural’ than it might appear. The reason they sometimes fail to taste like their fresh counterparts can be more complex than simple chemistry– which is why flavour wizards and foodmakers are employing clever new techniques to trick our senses.

So, why doesn’t banana flavour taste like banana? The answer is complicated – and it begins with a legend. There’s a story that the archetypal banana flavouring has very authentic origins; that artificial banana flavourings were developed from an old variety of banana called the Gros Michel. The Gros Michel, or “Big Mike” as it was affectionately known, was once prevalent in Western supermarkets.

That was until a ruthless fungus called Fusarium oxysporum, or “Panama disease”, all but wiped out the Gros Michel during the 20th Century. To keep consumers’ love of bananas satiated, producers cultivated a banana strain known as the Cavendish, which was resistant to Panama disease but which had a somewhat different flavour. The story goes that more pungent Gros Michel-derived flavourings persisted, which accounts for the dichotomy between banana flavourings and the commonly eaten fruit.

Banana myth?

However, if you dig in to this tale a little it soon becomes clear that there is little or no verifiable source that artificial banana is based on Gros Michel. “It sounds very, very unlikely to me,” says synthetic organic chemist Derek Lowe. “The thing is, banana can be mimicked most of the way with a simple compound called isoamyl acetate. Many chemists know it as ‘banana ester’ and anyone who smells it immediately goes, ‘banana!’ ”

Isoamyl acetate, which is indeed found in bananas, is a very simple compound that is both cheap to produce and highly versatile. Diluted, it smells more like pears than bananas and logical combinations of this ester have proved popular. Pear drops, for example, a well-known classic British sweet, contain both isoamyl acetate (banana flavour) and ethyl acetate (pear flavour).

Why doesn't the banana we pick off the shelf taste the same as its artificial counterpart? (Thinkstock)

Why doesn't the banana we pick off the shelf taste the same as its artificial counterpart? (Thinkstock)

Where, then, did the Gros Michel myth come from? Rob Guzman, a Hawaiian banana farmer, has a suggestion. He produces 35 different varieties – including the Gros Michel. It’s one of his top three favourite bananas and he says it has a very distinctive flavour.

“It’s almost like what a Cavendish would taste like but sort of amplified, sweeter and, yeah, somehow artificial. Like how grape flavoured bubble-gum differs from an actual grape,” he explains. “When I first tasted it, it made me think of banana flavourings.”

So while it doesn’t necessarily make sense to argue that banana flavourings “came from” the Gros Michel, the Gros Michel does appear to taste quite artificial. This ties in with analysis of its biochemical properties. Back in the 1960s, for example, the Gros Michel was compared to the Valery, a cultivar of the Cavendish subgroup. “A fuller and more interesting flavour was associated with the Valery fruit,” notes one text on the matter. “Confirmation by gas chromatographic studies showed fewer compounds and less volatile components for the Gros Michel compared to the Valery fruit.”

This hints that the Gros Michel does indeed have a biochemical profile that tallies with the idea of a more monotonous, less complex flavour. So perhaps there is some truth in the banana flavouring whodunnit after all. Once upon a time, banana flavourings really did taste more like the real thing.

The Cavendish banana - loved by monkeys and humans everywhere (Thinkstock)

The Cavendish banana - loved by monkeys and humans everywhere (Thinkstock)

The case of the Gros Michel suggests that we shouldn’t be so quick to label artificial flavours as “fake”. In many other flavourings, too, the chemistry is very similar to the genuine article – the reason they don’t taste the same is that they fail to reproduce other factors such as ripeness, age or flavours produced after cooking, for example.

There are exceptions to the rule. Vanillin is so dominant a compound in cured vanilla pods that simple vanilla flavourings synthesised in labs rather than extracted from organic matter are notoriously indistinguishable substitutes from “the real thing.” However, capturing the flavour of something like a whole, fresh and ripe strawberry in one compound is impossible.

That’s why today, there’s such a large market for moving beyond “one note” flavourings, says Danny Kite, senior flavourist at TasteTech in Bristol, UK. During the 20th Century, he explains, food and drink firms gradually realised that volatile compounds in foods lost during the storage of baked goods or the concentration of fruit juices for example could be captured and re-introduced to the product where possible.

“Over the years we’ve learned to trap those volatiles before they escape, condense them and then you have something that some people call an essence, some people call an aroma, but generally speaking you have a liquid which has a taste of the fruit,” he says.

The tricky part is in making sure that those volatiles are released at exactly the right moment – when a consumer is ready to eat the product in question. TasteTech achieve this through a special technology known as “encapsulation”, in which compounds are encased within a matrix of vegetable fat. In cooked foods, for instance, this can protect them from the heat of an industrial oven, so that they’re only released later, inside the mouth.

Sensory tricks

But encapsulation can do more than that. It can even allow for compounds to be released in stages while being eaten. This has led to, among other things, the production of longer lasting flavour in chewing gum.

Bompas & Parr, a London firm which specialises in unusual flavours and foods, has also experimented with multi-flavour products in an attempt to realise Willy Wonka’s Three-Course Dinner Chewing Gum. This was achieved by using some flavours which were micro-encapsulated that would therefore appear later, and other flavours which weren’t. The release of flavours, though, was additive rather than sequential.

“It’s not start and stop,” says co-founder Sam Bompas, “they start to layer up on top of each other and blend. But you can address that quite creatively if that’s a problem.” Bompas explains that you can simply tell people that a combination of flavours (such as strawberry and orange) is actually something completely different (pineapple).

TasteTech and Bompas and Parr have also used artificial flavours in fireworks (AFP/Leon Neal)

TasteTech and Bompas and Parr have also used artificial flavours in fireworks (AFP/Leon Neal)

Still, there are flavours which remain complex and difficult to capture. Kite points to the example of freshly ground coffee, the aroma of which is notoriously ephemeral. “A lot of those elements will react with the oxygen in the air and degrade very quickly,” he comments. “To make that flavour is almost impossible.”

But a canny knowledge of which foods share which compounds can lead to clever innovations in the field. Dave Hart, who once worked at the Institute of Food Research but now runs a coffee company, explains how he helped barista Alex Sergeant develop a competition-worthy coffee which sported the flavour of maple syrup. Normally when maple syrup is added to coffee it just makes the beverage taste bitter. But Hart knew that the key compound, dimethyl hydroxy furanone, which gives maple syrup its characteristic taste, also exists in fenugreek seeds, albeit in higher concentrations.

“What we did in order to make the maple syrup flavour,” he recalls, “was we fried up some fenugreek seeds in butter, added it to milk and got milk that tastes of maple syrup.”

Much of the flavour is experience is sensed with the nose, not the mouth (SPL)

Much of the flavour is experience is sensed with the nose, not the mouth (SPL)

Indeed, often our senses can’t be trusted to identify ‘authentic’ flavours. Everything from the colour of food to where we eat it, to what we’re told about it can affect our perception of flavour, says Charles Spence, professor of experimental psychology at the University of Oxford. “Most of what we experience as the taste or flavour of food really comes from our nose and is mis-localised by our brain so we think it’s coming from the mouth – a kind of ventriloquist’s dummy illusion,” says Spence. “And beyond that, all the other senses also play a role.”

Drink mix-up

For example, if you give someone two drinks to try in laboratory settings where one drink is 10% less sweet but another is coloured red, the subject will likely choose the red coloured drink as sweeter simply because of our associations between that colour and certain fruits. Spence argues that this could explain why consumers thought a promotional stunt where Coca-Cola was packaged in white rather than familiar red cans had a different taste – even though it was the same old Coca-Cola.

Even the sound of food can influence our perception of its taste. Spence says that we can tell if a liquid is hot or cold just by hearing it being poured because hot and cold liquids have different viscosities and our brains have somehow internalised the ability to perceive that difference aurally. This sort of ultra-specialist knowledge has led to consultative innovations with some of the world’s top chefs.

For example, Spence is currently collaborating with two-Michelin-starred Swiss chef Denis Martin. Martin has come up with a frozen gin and tonic dish, served as a perfect sphere. But because the sound of carbonation in the drink is now lost, so is some of the flavour. To this end, Spence has helped Martin wire up some of his plates so they can play the sound of carbonated bubbles floating to the surface of a G&T while the diners savour the frozen version.

Food tastes different on planes, so in-flight meal chefs have changed their menus (Thinkstock)

Food tastes different on planes, so in-flight meal chefs have changed their menus (Thinkstock)

Over time, flavour houses and flavour researchers incorporate this kind of knowledge into their testing so flavour production becomes increasingly nuanced. Cindy Beeren, a director at Leatherhead Food Research in the UK, says that her team tests foods and flavourings in deliberately sterile environments, under a specific type of white lighting called “northern daylight”. They’ve even tested samples at 30,000ft  where they found that the effect of monosodium glutamate, a common flavour enhancer, was reduced. Airline food companies, learning of this, were able to make their dishes taste more savoury using other methods to compensate.

Perhaps we shouldn’t be too quick to dismiss so-called fake flavours as uninspiring and unnatural. Instead, we might consider all the tricks that can make them taste fantastic. And next time you eat something banana-flavoured, sit back and marvel at how wonderfully complex it actually is. Unless, that is, you can get your hands on a Gros Michel.

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