So say researchers from Oxford Biotrans, a spin-off company of Oxford University scientists who have spent the past 20 years developing the technology.
They say it takes about four tonnes of grapefruit to create one kilogram of nootkatone. However, grapefruit supply varies from year to year with the harvest and also the whim of consumers – demand for the fruit and juice dictates the amount of by-product available for flavour extraction too, and demand has been shrinking for about 15 years even as demand for nootkatone has remained strong.
Other non-grapefruit derived sources of nootkatone exist, but Oxford Biotrans CEO Jason King says there are none that could be labelled as ‘natural’ – until now.
“Manufacturers are increasingly looking for natural flavours,” he told FoodNavigator. “There’s that pressure coming from manufacturers and consumers and we are responding to that demand.”
How does it work?
Oxford Biotrans produces nootkatone from valencene, a similar flavour compound from oranges, which have a plentiful and more stable supply. The process works by using an adapted version of the enzyme cytochrome p450 to add an oxygen atom and take away two hydrogen atoms from valencene, resulting in nootkatone. The enzyme creates the compound via a reaction with valencene but is not part of the final product.
King said EU labelling regulation – among the strictest in the world on use of the word ‘natural’ – was clear that the final product could be labelled as a natural flavouring, although it couldn’t be called ‘natural grapefruit flavour’.
Consumer perception of ‘natural’
“Price comparison with grapefruit flavour is still to be seen,” he said. “…There might be a premium because of the stability of supply but there may also be a discount because the suppliers may not be convinced that it is going to go over so well with consumers. It remains to be seen.”
The question of consumer acceptance is complex, and King said the company did not know whether consumers would care that the compound is not sourced from grapefruit. On the other hand, they may consider that the nootkatone, whether from grapefruit or from the company’s converted valencene, is molecularly identical no matter where it comes from.
“It’s more about how consumers respond, and then whether they care. A lot of it will be emotional responses rather than rational ones,” he said.
However, even if consumers question the flavour’s naturalness, King said: “The worst case scenario still looks good to us…Even the synthetic is highly priced.”
Additionally, he said the production of nootkatone in this way was partly about “proving that the technology works”, and opened other opportunities in flavours, fragrances, pharmaceuticals and natural pesticides.
On the flavours side, most demand for grapefruit flavour is in beverages, confectionery and baked goods, King said.
Oxford Biotrans said its nootkatone will be manufactured and marketed with flavour and fragrance firm De Monchy Aromatics.