Miracle fruit contains a protein called miraculin that tastes sweet enough to replicate the effect of sugar. Why isn't it widely used as a healthy sweetener?
Of all our senses, taste is the one that people associate most strongly with expectations of pleasure. But indulgence comes at a cost. Almost 45 percent of the American population will be clinically obese by 2030, according to current predictions. That will increase the total toll on the healthcare system from related illnesses, like diabetes and heart disease, to a staggering $60 billion.
And it’s not just in the United States. Over the past 30 years, global obesity rates have more than doubled, and behind the stark statistics is a simple truth about human nature. Most of us are bound by our innate desire for foods high in both sugar and fat, and given the opportunity to consume in excess, we will.
The values of healthy eating have been extolled for decades, but with little effect as the junk food industry has boomed. But perhaps the way forward is to work with our cravings, rather than attempt to deny them. For many, the Holy Grail of food research is to create a dessert free of both sugar and artificial flavoring that tastes as good as the real thing. The owner of a new coffee shop in downtown Chicago believes he has finally solved the puzzle.
As a chef and entrepreneur, Homaro Cantu has a reputation for an avant-garde approach to gastronomy. He believes the answer to one day eliminating sugar from our diets lies in a protein
known as miraculin which was first discovered almost 50 years ago. Miraculin is a taste-modifier, one of only a handful of such naturally-occurring molecules in the world. It is found in the berries of a plant known as Synsepalum dulcificum or, colloquially, the “miracle fruit,” which grows in parts of West Africa.
In 1725, the French explorer Reynaud Des Marchais was astounded to find that the locals regularly consumed the berry to improve the taste of bland or sour breads, but until the small explosion of research into the biological mechanisms at work at the protein level over the past decade, we didn’t really understand why.
The surface of your tongue is covered by a multitude of different receptors to detect tastes from sweet to umami. Just like sugar and artificial sweeteners like aspartame, the miraculin in the berry binds to your sweet taste receptors, but far more strongly.
The acid present in sour foods sparks a chemical reaction that causes miraculin to temporarily distort the shape of these taste receptors, enhancing them and making them so sensitive that the powerful sweet signals they are sending to your brain completely drown out the sour ones.
So far, miracle fruit has largely been used as something of a fine-dining gimmick at high-end restaurants from New York to Tokyo. Customers eat the berry and for the next hour, enjoy a “flavor-tripping” experience as sour turns to sweet in their mouths until the miraculin dislodges from their tongues.
So consuming the berry before you eat a sugar-free dessert will provide you with your ‘sweet fix’ but many believe that the full potential of miraculin has yet to be explored. Cantu has spent the past eight years working on a way to actually integrate the berry powder into foods so it has the same effect, starting with a doughnut.
However, this isn’t as easy as it might seem. Both refrigerating and heating miraculin causes the protein to activate, so its taste-twisting properties are sapped long before you sample the food. Cantu’s task has been to try and create a heat-stable form of miraculin, in order to cook with it.
With this new version of the protein, the effect only lasts for as long as it takes you to finish your doughnut.
“It’s the same reaction, but this time it happens in thousandths of a second,” he explains. “The miraculin will only latch onto your taste receptors for a small amount of time, just enough for you to enjoy the food that’s in your mouth.”
But if you’re expecting to be able to buy miraculin flavored doughnuts on the high street anytime soon, then think again.
The idea of introducing the miracle berry into food as a sugar replacement was actually first conceived almost 50 years ago by an entrepreneur called Robert Harvey who began to create a range of sugar-free products coated with the berry extract. Initially, his company Miralin appeared destined for instant success. In a poll in which schoolchildren were asked to choose between a sugary food and one of Harvey’s new treats, they voted overwhelmingly in favor of the latter.
However, things were about to change rapidly. The sequence of events which ensued would not look out of place in a Hollywood film. Harvey began to suspect that he was being followed on the way home from work; then one night in the summer of 1974, he reported that his office had been raided and his files stolen.
Shortly afterwards, the previously supportive Food and Drug Administration (FDA) declared that miraculin was an additive, meaning that the berries could not be sold as a sugar substitute without further testing. Harvey suspected foul play. He suggested that the FDA had been pressured by the powerful manufacturers of sugar and artificial sweeteners, keen to quash this new challenge to their business, something both parties denied.
“For the FDA to overturn the ruling, as far as I understand it, would require years of testing and a large amount of money, which it was not possible for Harvey to raise in the poor economic climate of 1974,” explains Canadian author Adam Gollner, who chronicled Harvey’s story in his book, The Fruit Hunters.
And so for the next 30 years, the berry was largely forgotten, knowledge of its existence preserved only by a small group of fruit enthusiasts—until Cantu’s new venture.
As the FDA ruling stands, it is possible for the berry to be distributed to customers in restaurants and coffee shops but any food product containing it would only able to be marketed and sold outside the United States.
When The Atlantic asked if they would consider changing the ruling, the FDA released the following statement: "In 1977, the agency concluded that information submitted regarding miraculin did not support either a 'generally recognized as safe' (GRAS) affirmation or the issuance of a food additive regulation. The FDA has not received further information on the safety of the use of this substance in food under either the GRAS program or a food additive petition."
However, Gollner believes that if Cantu or others were to make a serious challenge to the FDA’s ruling, they would almost certainly get it overturned.
“Anyone wanting to go down that route would likely be successful, as there is nothing unhealthy about miraculin. They'd just need to have the financing and patience to see it through. Researchers have concluded that miracle fruits are entirely safe even in massive doses. A $100,000 toxicology study undertaken by Miralin demonstrated that rats eating miracle fruit concentrate were healthier than those eating pet food. It had no ill effects, even at 3,000 times ordinary human consumption.”
Cantu is hopeful this can be achieved by actually forming partnerships with the giants of the junk food world in order to create healthier products.
“We want to get sodas that have zero amounts of sugar, provided by a berry which amounts to 1 calorie,” he said. “There’s a company out there that’s interested in that. But we want everybody to use it, whether its small entrepreneurs opening up sugar-free soda shops, or the major junk food organizations.”
For many years, the idea of replacing sugar with miraculin was unattractive to large organizations for cost reasons. When harvested from its natural West African environment, miracle fruit has a price point comparable to truffles. On one website, about 10 grams of freeze-dried miracle fruit powder costs $30.
The reason is that it takes around four years for every miracle plant to grow and just one out of four plants will bear fruit. Back in the 1960s, Harvey's company solved this problem by growing miracle fruit outdoors on a large scale at a number of farms but today, the cost of the farm land for such an endeavor would be far more expensive.
As a result, some scientists have been seeking to lower the price through bioengineering. A team of researchers at the University of Tokyo are working on genetically modifying tomato and lettuce plants, as a way of cultivating the miraculin.
“Tomatoes are particularly suitable,” Dr. Hiroshi Ezura explains. “The production protocol is well established and you can use the juice and freeze-dried powder from the genetically modified crop. This contains the miraculin. Natural miraculin is rather expensive, which is why it has not yet been used in foods. But with our GM technology, we estimate that we can produce it at one one-hundredth of the cost, and we see no molecular differences between natural and GM miraculin.”
Cantu believes that compared to the sugary alternatives in the grocery store, genetic modification techniques are far too expensive to ever compete and become a reality—but he has an alternative solution.
His method has been to set up large indoor farms and grow the berry himself in-house. Cantu claims that his plants grow up to 50 percent faster than genetically modified plants, and with lighting, temperature, and monitoring technology becoming ever cheaper, he says he can develop products that would sell at prices equivalent to those in supermarkets.
“Once the berry bushes get going, you can get up to three or more crops in a year and each bush can produce 800 berries. That’s a ton in a small space,” Cantu said. “It’s taken over three years to get our indoor farm efficient enough to be comparable with the shops, but we can now produce these berries at a fraction of the cost of sugar. And when you think of the amount of energy that sugar takes to grow, the processing and the food mile, there’s no comparison.”
Large-scale indoor farming may well prove to be the future and once collaborations are formed, Cantu believes there’s no reason why industry would not want make a straightforward switchover from sugar to miracle fruit.
“Ultimately, after you experience what miraculin can do, there’s just no good reason why we would continue using sugar.”