Biotechnology as a source of natural volatile flavours

•Microorganisms and enzymes generate volatile flavours on the industrial scale.•Side-streams of food processing provide an abundant source of flavour precursors.•Biocatalysts from transgenic sources are powerful, but may lack social acceptance.•Advances in bioprocessing and novel genetic techniques boost the product yields.

It has been a long way from the endogenous flavour-forming microflora of traditional fermented food to genetically engineered prokaryotic and eukaryotic flavour producer strains in fully controlled bioreactors. More than 100 flavours from advanced bioprocesses are commercially available. Apart from its inherent principal advantages, biocatalysis matches the increasing re-orientation to sustainable industrial processes. To create valuable and pure food flavours in high yields from low-valued industrial side-streams using metabolically streamlined, safe microorganisms in specifically engineered bioreactors has been a vision which turns more and more into reality.