A designer protein engineered as an alternative to sugar is poised to hit markets and, if effective and safe, could trigger a paradigm shift in our exposure to one of the most addictive — and hazardous — aspects of our diets.
A research effort by Israeli food tech startup Amai Proteins aims to the solve the problem at the root — our taste receptors for all things sweet. The company is testing a bacteria-synthesised protein, monellin, that docks to the same sweet receptors as sugar, but delivers over 3,000 times the sweetness.
Isolated from the serendipity berry found in West Africa, monellin was discovered in 1969 — but it is only now that it could start to reach shelves around us. Amai Proteins is aiming to use monellin protein to replace up to 70 per cent of added sugar in the food we eat.
The difficulty of replacing sugar
Sugar, a known culprit behind diabetes and obesity, is found in much of the food that we eat. Its most accessible substitute, artificial sweeteners like aspartame, is linked with carcinogenic properties.
The gut microbiome, a world unto its own, may worsen the sugar addiction, as gut microbes send signals to the brain demanding more sugar. At a neurobiological level, sugar triggers addiction in much the same way as cocaine.
All this adds up to a significant challenge when it comes to finding an effective replacement for sugar. One problem is that the replacement must taste as good, the other is that it should not prove as unhealthy as sugar. A bioengineered solution, then, must tick many boxes.
Also read: Emerging link between sugar and depression
Making a designer proteins
Taking any new food additive to market requires blending expertise in a range of disciplines. Monellin loses its natural structure at just 45 degrees Celsius. With such high temperatures common in food processing, modifications were necessary to make it more stable.
Using a method called agile integrative computational protein design (AI-CPD), Amai Proteins tweaked its structure to improve its stability, inspired by the biomechanics of extremophile organisms that can survive the harshest conditions.
Manufacturing the protein requires the compliance of bacteria, nature’s own factory workers. The designer protein is made in yeast, and upon harvesting, becomes a white powder called sweelin.
In food tests, the company has reduced the sugar content of ketchup by 70 per cent and in that of chocolate by 50 per cent. Notably, “supertasters” (those with an enhanced sense of taste), could not tell the difference, Ilan Samish, Amai’s Founder and CEO, said in a Nature article.
At the level of the body’s second brain, the gut, the protein is believed to be unlikely to interact with the gut microbiome. Crucially, it is digested into amino acids without activating an insulin response.
In markets soon?
Amai Proteins hopes to launch the product commercially this year after receiving “Generally Recognised as Safe” status from the US Food and Drug Administration. “Old-school agriculture cannot be sustained; we need to produce new tasty, healthy, cost-efficient, and sustainable designer proteins for the mass food market. This is what we can do with synthetic biology,” Samish says in the Nature article.
Monellin may join the ranks of other designer proteins that aim to substitute for sugar, such as Stevia’s offering, as well as natural options like the monk fruit extract.
