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Synthesizing the Future

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It’s no surprise that a large and growing percentage of the population have a preference to the word “natural,” as opposed to the word “artificial” when associated with their food, fragrance, medicine, cosmetics and other consumer goods. Even when the two are chemically identical and show no difference in their effectiveness, most people would choose the natural option than the artificial one.

Natural continues to be strongly linked with a positive effect. This preference is, in general, stronger in food and personal care products than in medicines, mainly because natural products are thought to be healthier, more appealing to the senses and kinder to the environment. There is also a comparatively strong moral reasoning that natural products are not only beneficial to the individual but to society at large. The preference doesn’t change even when it is clear to the consumer that both the natural and artificial product are chemically identical.1 There also appears to be a strong link to the “naturalness” of the product or ingredient in the consumer’s mind with the way in which they were derived. Chemical transformations reduce the “naturalness” of the material much more than physical transformations, and processes such as mixing materials have little effect on the consumer’s perception. In addition, the history of ingredient processing is more important for the consumer’s assessment of its naturalness than the nature of the ingredient’s contents.2

In response to the consumer perception that natural is better, brands have pushed to remove ingredients from their products that give a negative image to the product to be perceived as being healthier (see F-1). However, as we can see from Panera Bread’s “No No” list, there is little in the way of science behind this - synthetic vanillin is not allowed but natural vanillin is, despite both being chemically identical molecules.

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There are significant challenges ahead for the F&F industry if it wishes to continue to use synthetic materials in its formulations. Some of these challenges can be combatted by educating the consumer, and to that effect the recent decisions by Proctor & Gamble, Unilever, SC Johnson, Clorox and Henkel to disclose the ingredients used in their fragrance formulations are positive moves to greater transparency and trust with the consumer. A 2016 study by Label Insight3 reports that 73% of consumers are willing to pay more for a product that communicates transparency, and 94% are likely to be loyal to a brand committed to full transparency. It seems, then, that consumers are willing to accept ingredients which have been synthesized, if there is some transparency around their inclusion in a product.

Chemicals are Evil?

We can conclude that consumers are wary of not only chemicals but also the process in which these chemicals are derived from. A series of experiments in the 1970s and 80s by Daniel Kahneman (Nobel Laureate in Economics) showed how people make judgements under conditions of uncertainty. These experiments demonstrated that we as humans prefer to avoid losses over acquiring gains.4 Apply this to the public’s perception of the chemical industry and to the F&F segments in particular, and it becomes easy to understand why consumers put more weight on information that suggests something can harm us over information that suggests that there is no difference between two sources.

The vast majority of consumers have little understanding of chemicals and chemistry and simply get confused and concerned by chemical names. For example, tell someone that their green tea or blueberries are good for them because they contain anti-oxidants, then they have an increased level of confidence that their purchase of the product is giving them a health benefit. Tell them instead that they contain polyphenols, and they may be mildly confused, but as the benefits of polyphenols become more widely understood and accepted, then they can overcome that confusion. One step further: simply tell them that a product has (2R,3S)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5,7-triol and there is a good chance they will run a mile claiming that the government is trying to poison them.

Add this to some of the chemical and chemical industry-related incidents over the years, such as Bopal, Flint, Flixborough, Texas City and Toulouse or the more recent explosion at a fertilizer factory in West Texas (of which there are some interesting clips on Youtube), and we can see why consumers have such a fear of chemicals, and view the chemical industry as a major polluter and threat to society.

Despite these perceptions, the problem is that we need chemicals. There have already been numerous articles in this publication alone about the benefits that molecules bring to the creative process, so how do we get around this fear?

Can We Have Another Earth, Please?

While some sections of society think it would be nice to be able to source everything from a cultivated feedstock and remove synthesized chemicals completely, we must remember a couple of things. The consumer, I’m sure, would gladly accept fragrances and flavors created from extracts, distillates, absolutes and essences of plants that they can easily identify and connect with. However, if we were to cover the majority of notes and tastes the perfumer and flavorist would need, realistically this wouldn’t be feasible. Firstly, not every material used in the creation of flavors and fragrances, whether it is a natural complex substance (NCS) or a distinct chemical molecule, occurs in nature. Some of the key building blocks in fragrance creation in particular, such as dihydromyrcenol, Habanolidea and delta damascene, are not naturally occurring, and to remove these from the perfumer’s palette would cause significant problems.

A wider issue, and one which will take on greater significance in the immediate future, is the question of resource. The global population has seen significant growth over the last century with the expectation that by 2048, it will reach nine billion people. We can determine that if we continue at this current rate, we will need 2.3 Earths to be able to satisfy the needs of nine billion people (F-2). Previously published fragrance industry data from Perfumer and Flavorist5 shows us that over 75% of the materials used (excluding solvents) in fragrance creation are synthetic ingredients from non-renewable feedstocks. Of the remaining 25%, only 7% stem from ingredients that the consumer would classify as “natural.”

We could expect that the industry should focus on the 7% of ingredients, which come from natural sources to help solve the conundrum. By focusing more on these cultivated sources, we could potentially make headway into the problems of resource. Unfortunately, this doesn’t appear to be possible. In a 2013 report, the Research Institute for Fragrance Materials (RIFM) examined a selection of fragrance ingredients such as dihydromyrcenol, hexyl salicylate and patchouli oil.6 The results in terms of the CO2 emissions, water consumption and energy used give interesting results (F-3).

So it seems even though the consumer prefers products made from ingredients more closely obtained from cultivated sources, and more recognizable as natural, doing so is considerably more resource-intensive than synthesizing chemicals. From all of this, two things are clear: our industry absolutely needs synthesized materials, and the consumer doesn’t understand or trust them.

Where Do You Get Your Carbons?

If 75% of the feedstocks used to create fragrances are from petrochemical sources, and 7% from natural sources, then where are the remaining 18% coming from? The answer is that these ingredients are synthesized from renewable feedstocks such as crude sulfate turpentine, gum terpentine and citrus by-products such as d-limonene.5 A quick review of the FEMA GRAS lists gives a similar picture, in that the overwhelming percentage of ingredients used in creation are distinct molecules that are synthesized. As much as the consumer would like it, we can’t get away from synthesized materials.

We have to remember that in the short term, we operate in a consumer driven market, but in the longer term we have the capability to shape consumers’ thoughts and preferences. At this time consumers don’t necessarily understand or trust chemicals but will be loyal to brands offering transparency. By offering greater transparency aligned with rigorous testing and supportive communication in the long term, we should be able to develop a level of confidence in the ingredients the F&F industry is using.

So should there be more focus and investment in producing synthetic ingredients from renewable feedstocks? Undoubtedly the answer has to be “yes,” so we can not only solve the issue of resource and environmental impact, but also address the challenge of consumer confidence in synthetics. Unfortunately, as we stand, the only chemical class of ingredients where there are viable economical and synthetic routes from renewable feedstocks are towards terpene chemicals, which currently represent about 40% of the aroma chemicals used by value in F&F compounding (F-4), and not all of these are made from renewable feedstocks. There have been some moves towards more renewable feedstocks, with companies such as Takasago launching products like Biomuguetb from their Sustainable Scentc brand, which utilize renewable sources and green chemistry.

Over the past decade, a large proportion of the chemical industry has shifted its attention towards examining the potential to create value from food waste. Around 90 million tonnes of food waste are generated in the EU alone each year and the majority is a result from processes within the food industry rather than household or supermarket waste. Valorizing waste components could in fact lead to numerous possibilities for the production of valuable chemicals. Work has already been undertaken that shows that food biomass can be converted into various fuels7 or converting comparatively abundant waste streams such as spent coffee grounds.8 Additionally, biocollagenic materials with healing properties can be obtained from meat and leather waste by various extraction processes.9 These methods of conversion use traditional chemical routes. However, there are other ways in that waste streams can be converted into valuable intermediates. For example, bakery waste can be converted into succinic acid by selecting certain microbial strains in fermentation processes.10 By committing resource to creating value from what has been traditionally viewed as waste streams, other areas of the chemical industry have discovered innovative solutions from currently available, renewable resources. The F&F industry has begun look in this area also, and I would anticipate in the medium term this approach will bring its rewards.

The biotech approach is becoming more common within the F&F world, as it shows how complex but desirable materials can be used in food production, such as various vitamins and essential fatty acids, can be produced.11 There have also been successes in the biotech field, which have resulted in the direct production of aroma chemicals which are available today. For example, Firmenich’s Clearwoodd is a patchouli-type material and is result of their white biotechnology platform. Biotechnology has also been able to produce versions of currently available molecules such as vanillin,12 gamma decalactone13 and 2,4,6-tris(2-methylpropyl)-1,3,5-dithiazine (bacon dithiazine).14

This quite neatly brings me back to ingredients produced from natural sources. It has already been shown that the production of extracts, distillates, oils and absolutes is extremely carbon and water intensive. One of the areas where the biotech approach could bear fruit within the industry is the valorization of waste streams from the production of these products. Often these by-products are treated as waste, or sold for animal feed, which although this generates some value no doubt as technology evolves a number of other potential opportunities to create further solutions could arise. This could benefit the F&F industry in a number of ways. Farmers’ livelihood relies on crops, which as we have seen with Vanilla and Citrus, are in a precarious position whether this is because of climate related events, pestilence or outdated farming methods. Having the potential diversify their income streams, and becoming less reliant on producing “perfect” crops can only benefit comparatively low income communities who rely heavily on farming. The F&F industry has the potential to pursue this route. We are already strongly connected to the farmers who cultivate these crops, and so by working alongside them to create further benefit the industry moves to be not only environmentally responsible, but also socially and economically responsible – something which strikes a chord with a growing segment of the population and which could be used further by food, beverage, personal care and consumer product manufacturers in their product positioning.

This raises a number of questions. Could we produce materials from naturally occurring sources which are chemically close to the cultivated feedstock? Could this offer the opportunity greater transparency? Would the consumer have greater confidence in flavor and fragrance ingredients that are produced from natural sources? Would the consumer see a greater connection of these materials to the natural world they desire? Can we shift the debate away from natural versus artificial to renewable versus non-renewable? Should we be promoting the production of materials from natural sources, rather than focusing on whether they are “natural” or “artificial?”

Tomorrow’s Synthetics

Whether produced through traditional chemical synthesis or through biochemical transformations, it is clear that the industry must continue to invest in the development of new synthetic molecules. The question is what type of molecule we need. We could argue that pretty much every odor profile is covered by materials that are currently available, and the creative energies of perfumers and flavorists should be able to use the current material palette to create just about every odor profile the consumer needs. This should not dampen our enthusiasm for discovery of new aroma molecules, whether driven by a need to improve on currently available odor profiles or concerns regarding safety (proven by sound science rather than public perception), or even by new discoveries from nature.

Beyond simply adding to our odor palette, there are other factors in determining synthetic use and their benefits. Areas such as sweetness enhancement, salt reduction, fat reduction and bitterness blocking, driven by consumers’ greater understanding of the nutritional needs of the food they eat, has led to a growth in better-for-you products. We now have a far greater understanding of the interactions beyond odor at a receptor level, and how this contributes to our acceptance and enjoyment of the food we eat.

It has long been established that our sense of taste detects four basic sensations – sweet, salty, bitter, sour. The savory or umami effect is a more newly established effect and is known to be linked to chemicals with a glutamate structure in them. That human mother milk has high levels of glutamates indicates that we learn from an early age to appreciate this effect. The presence of glutamates in many other foods such as fish, cheese, tomatoes, peas and corn add to our liking for these foods. Other chemical structures have been found to exhibit umami character, such as the nucleotide inosinic acid, and the effect is unusually observed in the menthol derivative, N-isopropyl-5-methylcyclohexyl cyclopropanecarboxamide (F-5), where the structure is more associated with cooling.

While our understanding of these receptor mechanisms is clearly growing, there is much less reported data from research to enhance our understanding of the types of chemical structures that specifically trigger these receptors. There are, of course, naturally occurring materials currently available that can provide these effects. These materials often come with an odor which may not be desirable in the finished product and require additional work to formulate around. As the importance of providing these types of taste modulation effects grows, we should expect that the development of synthetic molecules to create these effects also grows. Additionally, we should expect to see the breadth of materials providing a gustatory effect, without imparting an increase in odor.

Ouch, That Hurts, But I Like It – Chemosensory Irritation

Chemosensory irritation (chemical “irritants” in the mouth, nose and skin) give rise to sensations such as pungency, warmth, cooling and tingling. These can often be desirable in food, beverage, cosmetic and personal care products. Such chemesthetic effects are often expected in naturally food ingredients. Alongside their obvious odor components, spices such as capsicum, cinnamon, cassia and ginger provide a warming in the oral cavity; other spices such as mustard, horseradish and wasabi provide a more nasal warming. Cooling spices such as mint and eucalyptus, numbing spices such as clove and wintergreen, as well as tingling spices such as jambu and Szechuan pepper.

These effects are activated when chemical stimuli excite the sensory neurons of the dorsal or trigeminal ganglia. These receptors belong to the class of transient receptor potential channels (TRP) of which seven subsets exist (TRPC, TRPV, TRPM, TRPA, TRPP, TRPML & TRPN). There are a relatively large number of known agonists, with some examples in F-6. However, the majority of these are present in botanical sources and come with an unwanted (sometimes) odor attached, which can limit where a perfumer or flavorist could potentially use them.

As with sweet, sour, bitter, salty and umami effects in some of the areas of chemesthesis, there is limited understanding of chemical structure and TRP channel effectiveness. In the majority of areas, the agonists continue to be derived from natural sources. The notable exception in this is in the area of cooling where there has been a large amount of effort to synthesize more effective molecules than exist in nature resulting in a much wider array of materials, and a better understanding of structure/property correlation17. There still exists significant potential to create further molecules that target specific TRP channels, providing target sensory chemesthetic effects that may not have the handicap of an attached odor.

The Final Frontier

While there is currently—and there probably will be for the immediate future—a considerable amount of noise around the synthetic ingredients used in flavor and fragrance, the reality is the future of F&F industry lies in how we use the resources around us more effectively and communicate to the consumer the safety and benefits of what the industry does.

Our ability to synthesize specific molecules, which target a specific gustatory or trigeminal function, along with potential solutions that biotechnology, green chemistry and waste valorization bring to the materials we currently use, or those we wish to create, mean that synthesized ingredients are the future of our industry. We must continue to focus on utilizing technology to bring benefits the consumer desires and recognizes. The challenge we face is how the food, beverage, personal care and consumer product companies create a message, with the support of their F&F partners, that synthetics are not only good for you but good for the planet. The answer might be, to paraphrase Star Trek, “It’s synthetic Jim, just not as we know it.”

Related Content

 

Close

F-1

Brands that are removing negatively perceived materials from ingredient list

F-2

Global resource growth

F-3

Renewable and non-renewable emissions from dihydromyrcenol, hexyl salicylate and patchouli oil

F-4

Global aroma chemicals market

F-5

Non-glutamate chemical structures giving an umami effect

F-6

Popular chemical agonist

References

 

  1. Rozin, P., Spranca, M, Krieger, Z, Neuhaus, R., Surillo, D., Swerdlin, A, & Wood, K.; Natural preference : Instrumental and ideational/moral motivations, and the contrast between foods and medicines. Appetite, 43, 147-154 (2004)
  2. Rozin, P. The Meaning of Natural : Process more important than content, American Psychological Society, 16 (8), 652-658 (2005)
  3. https://www.labelinsight.com/transparency-roi-study
  4. Kahneman, D. & Tversky, A., Amer. Physcologist, 39 (4), 341-350 (1984)
  5. Kulke, T., Perfumer & Flavorist, June 2015, pp16-23
  6. RIFM’s “Lifecycle Assessment of Selected Fragrance Materials”, http://www.rifm.org/rifm09/upload/RIFM-IFRA%20LCA%20of%20Selected%20Fragrance%20Materials.pdf
  7. Atsumi, S., Hanai, T., Liao, J.C.: Non-Fermentative pathways for synthesis of branched chain higher alcohols as biofuels, Nature, 451, 86-89 (2008)
  8. Calixto F., Fernandes J., Couto R., Hernandez E.J., Najdanovic-Visak V., Simoes P.C, Synthesis of fatty acid methyl esters via direct transesterification with methanol/carbon dioxide mixtures from spent coffee grounds feedstock, Green Chem, 15, 518-524 (2013)
  9. Catalina, M., Cot, J., Borras, M., De Lapuente, J., Gonzalez, J., Balu, J.M., Luque, R., From Waste to healing Biopolymers: biomedical applications of biocollagen extracted from industrial residues in wound healing, Materials, 6, 1599-1607 (2013)
  10. Zhang, A.Y., Sun, Z., Leung C.C.J, Han, W., Lau, K.Y., Li, M., Lin, C.S.K, Valorisation of Bakery Waste for succinic acid production, Green Chem., 15, 690-695 (2013)
  11. Agapakis, C., McDonnell, K., Perfumer & Flavorist, 42(6), 42-49 (2017)
  12. Rabenhorst, J., Hopp, R., Process for the preparation of Vanillin and microorganisms suitable therefore. US Patent 6133003 A (2000)
  13. Farbood, M.I., Willis, B.J., Production of g-decalactone. US Patent 4560656 (1985)
  14. http://www.prnewswire.com/news-releases/blue-marble-biomaterials-releases-us-and-eu-natural-bacon-dithiazine-flavor-ingredient-300309907.html
  15. Nelson G, Hoon MA, Chandrashekar J, Zhang Y, Ryba NJ, Zuker CS, Mammalian sweet taste receptors, Cell, 106(30), 381-390 (2001)
  16. Adler, E, Hoon, MA, Mueller KL, Chandrashekar J, RYba NJ, Zuker CS, A novel family of mammalian taste receptors”, Cell, 100(6); 693-702 (2000)
  17. Pringle, S., Types of Chemethesis II : Cooling in Chemesthesis : Chemical touch in food and eating, (Ed. McDonald S.T., Bolliet, D.A, Hayes, J.E), Wiley Blackwell, pp106-133 (2015)

 

Footnotes

 

a Habanolideis a registered tradename of Firmenich

b, c Biomuguet and Sustainable Scent are tradenames of Takasago

d Clearwood is a registered trademark of Firmenich

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