The true taste of strawberry: Researchers reveal mechanism to allow biosynthesis of key aroma compound

The team of German researchers believe they have found a previously unknown molecular pathway that may help to better  produce the major strawberry aroma compound HDMF (4-hydroxy-2,5-dimethyl-3(2H)-furanone).

Led by Professor Wilfried Schwab from the Technical University of Munich (TUM) the research team explained that ripe strawberries  have a particularly high concentration of the compound that helps to give them their 'characteristic caramel-like aroma.'

"We were particularly interested in the biocatalytic process that leads up to the final compound," ​explained Professor Arne Skerra from the TUM, who was also involved in the project.

By mapping the reaction pathway for the production of this compound in detail, the TUM team were able to gain a better understanding of how enzymes catalyse the biosynthesis of the compound - discovering that the catalytic reaction involved an until now unknown mechanism.

"Unlike coffee or vanilla, the biochemical processes that produce the strawberry aroma are very complex,"​ Skerra said. "But now our TUM research team has shed light on an important step in its biosynthesis."​

As a result, the team believes that a biosynthetic processes could soon be used to produce the compound - which could be used in food and drink products to help them 'taste even more like the real thing.'

Aroma perception​

The smell of a food plays a vital role in our perception of its taste by helping to build a more 'rounded' taste experience than we are able achieve with our tongue alone.

As a result, the production of aroma compounds that are identical to those present in real fruits an important process that can help to produce products that are better perceived by consumers.

The authors noted that the characteristic aroma of a fresh strawberry is the result of around a dozen different aroma compounds - however one in particular (HDMF) plays a key role.

Study details​

The team found that in plants, the aroma compound develops in a multi-step pathway from the from the fruit sugar fructose. As part of this process the team discovered that a molecule precursor binds an enzyme known as FaEO (Fragaria x ananassa enone oxidoreductase) which converts it into HDMF.

"We investigated altogether six different enzyme-molecule combinations – and ended up understanding how FaEO produces the HDMF flavour compound,"​ explained Dr. André Schiefner - who also worked on the research.

In the course of this research the scientists found that that the compound is reduced, and electrons are specifically transferred to a particular part of the molecule.

As a result the team suggested that the FaEO enzyme represents the first member of new class of biocatalysts – a discovery which could lead to useful applications in industrial biotechnology.