Sustainable Flavour and Fragrance Extraction

Historically, plant extracts have been the source of flavours for our food as well as fragrances for our soaps and perfumes.

More recently, these natural products have been ousted by chemicals synthesised from petrochemicals, which have the advantages of both price and of a raw material supply unaffected by seasonality, drought or pests. Perhaps the best example is vanilla flavour. Extracts of vanilla bean have long been replaced by synthetic chemicals produced using petrochemicals or byproducts from the paper industry.

Demand for Natural

But now the tide is turning again. Consumers are increasingly demanding natural products, which are seen as healthier and more eco-friendly. In personal care particularly, ‘natural’ products have gone from being a niche industry to becoming a mainstream consumer demand, with the global market predicted to grow from 34.5 billion dollars in 2018 to around 54.5 billion dollars by 2027. This shift is being accelerated by increasingly sophisticated natural product extraction and innovation in biotechnology.

Natural Extraction Technologies

New methods are being developed for natural product extraction that are free from hazardous solvents and gentler, making them better able to capture delicate aromas and flavours.

• The Spinning Cone Column uses centrifugal forces to create a thin liquid film. Volatiles evaporating from this film are then extracted using steam. The process can operate at relatively low temperatures, enabling it to capture the fresh light notes of fruit, vegetables or tea.
• Microwave radiation provides rapid and uniform internal heating and can be successful at extracting compounds such as essential oils from plants. It can be coupled with other techniques such as hydro-distillation to improve their effectiveness.
• Supercritical carbon dioxide extraction can be used for the separation of materials such as waxes, lipids and secondary metabolites from solid materials. This method of extraction is commonly used for the removal of caffeine from tea and coffee.

Sustainable Extraction Technologies

To make matters even more sustainable, some of these new extraction technologies are being used to find value from waste. Bio-bean are the world’s largest recyclers of coffee. They have found that brewing does not completely remove all the natural chemical compounds in the coffee beans. Up to a third of the aroma and flavour compounds can be left behind and these can be extracted from the spent grounds and used as flavouring products.

A Biotech Approach

A radically different approach is to use biotechnology – fermentation by microbes, such as yeast or bacteria – to produce flavour compounds. The perfume industry must be the ultimate market for high-value, low volume compounds. Ambrox is a perfume ingredient with a woody, musky scent that was first synthesised in the 1950s as a replacement for ambergris, which is excreted by sperm wales. Swiss Company Firmich has been successfully producing it at scale using fermentation since 2016.

It has proved harder to make biotechnology competitive for the food industry, but there are some successful pioneers. For example, Dutch biotech company Isobionics is supplying valencene, which has the smell and taste of oranges. Their biotech valencene is equivalent to that produced by the orange plant but is available year-round and comes with a lower environmental price tag. The company has calculated that you need 160,000 oranges to make one litre of valencene (not to mention the water you need to grow the orange crop, fuel to transport it and work to extract it), but less than a kilo of sugar to produce the same amount by fermentation.

Waste Not Want Not

To make matters even more sustainable, some of these new technologies are being used to find value from waste. For example, microwave treatment of orange peel can be used to release oils and volatiles such as limonene and terpineol.

For an example of how big companies are thinking, just take a look at Croda. This Yorkshire-based multinational sells specialty chemicals for a wide range of sectors. As part of their sustainability targets they have committed to make over 75% of their organic raw materials by weight bio-based by 2030.

This story is set to just grow and grow…

Do you prefer using products that contain plant extracts? If so, why?