How a Human Smell Receptor Works Is Finally Revealed

A space we worked for Coffee smells and tastes

How a Human Smell Receptor Works Is Finally Revealed

After decades of frustration, researchers have determined how an airborne scent molecule links to a human smell receptor.

Wynne Parry,  Contributing Writer, May 1, 2023  in Quantamagazine.

For the first time, researchers have determined how a human olfactory receptor captures an airborne scent molecule, the pivotal chemical event that triggers our sense of smell.

Whether it evokes roses or vanilla, cigarettes or gasoline, every scent starts with free-floating odor molecules that latch onto receptors in the nose. Multitudes of such unions produce the perception of the smells we love, loathe or tolerate. Researchers therefore want to know in granular detail how smell sensors detect and respond to odor molecules. Yet human smell receptors have resisted attempts to visualize how they work in detail — until now.

In a recent paper published in Nature, a team of researchers delineated the elusive three-dimensional structure of one of these receptors in the act of holding its quarry, a compound that contributes to the aroma of Swiss cheese and body odor.

“People have been puzzled about the actual structure of olfactory receptors for decades,” said Michael Schmuker, who uses chemical informatics to study olfaction at the University of Hertfordshire in England. Schmuker was not involved in the study, which he describes as “a real breakthrough.”

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He and others who study our sense of smell say that the reported structure represents a step toward better understanding how the nose and brain jointly wring from airborne chemicals the sensations that warn of rotten food, evoke childhood memories, help us find mates and serve other crucial functions.

The complexity of the chemistry that the nose detects has made olfaction particularly difficult to explain. Researchers think that human noses possess about 400 types of olfactory receptors, which are tasked with detecting a vastly larger number of odoriferous “volatiles,” molecules that vaporize readily, from the three-atom, rotten-egg-smelling hydrogen sulfide to the much larger, musky-scented muscone. (One recent estimate put the number of possible odor-bearing compounds at 40 billion or more.)

“In my mind, one of the most amazing things about olfaction is our ability to detect and discriminate such a wide array of volatiles,” said Hiroaki Matsunami, an olfaction researcher at Duke University and an author of the new study.

Caught in the Act

Perched on the surface of neurons in the nose, olfactory receptors change shape when they snag odor molecules. This reconfiguration prompts the neurons to send signals to the odor-processing parts of the brain. Researchers have long sought to see in detail how the interaction between receptor and odor molecule plays out. .... ' 

Odors In Virtual Worlds

 Again, a space we experimented in, especially with regards to coffee.  Here more VR related.

Scientists have come up with a new way to introduce odors into virtual reality via small, wireless interfaces. 

Creating smells in virtual reality is a vexing problem that has prevented consumer VR devices from offering a full sensory experience in most settings. “People can touch in VR,” says Xinge Yu, a professor at the department of biomedical engineering at the City University of Hong Kong and the lead author of the new paper, published today in Nature Communications. “And of course, you can see and hear in VR. But how about smell and taste?”

Previous efforts to create odors in VR have involved multiple wires, messy liquids, and bulky contraptions that don’t lend themselves to home use. 

To tackle the problem, Yu and his co-author, Yuhang Li of Beihang University in Beijing (both of whom have backgrounds designing flexible electronics), developed two wearable interfaces. One can adhere to the skin between the nose and mouth like a bandage; the other straps on beneath a headset like a face mask.

Both types of interfaces use miniaturized odor generators, a grid of tiny containers filled with perfumed paraffin wax. When a heat source beneath the wax is activated, the wax heats up, essentially becoming a scented candle capable of reproducing multiple odors within 1.44 seconds, according to Yu and Li. When the experience is over, a copper coil kicks a magnet to tamp down on the wax and cool down, ending the scent.

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The higher the heat, the stronger the odor and the more easily identifiable the smell, Yu says. That means that interfaces can get very hot—up to 60° C (140° F), which is dangerous for human skin. But Yu says the interface is safe because of an “open” design that lets hot air escape, along with a piece of silicone that forms a barrier between the skin and the actual device.

In a test with 11 volunteers, the interface that goes between nose and mouth was judged safe so long as it was at least 1.5 millimeters from the nose, with a temperature at the skin’s surface of 32.2° C, or 90° F—less than human body temperature. Yu realizes, though, that a scalding hot interface attached to your face might not feel safe enough to use, and he said he and Li were testing ways to make the interface run at lower temperatures or cool down more efficiently.

Yu and Li are not alone in trying to create seamless olfactory experiences in VR. At this year's CES, OVR Technology announced that it would release a headset containing a cartridge with eight “primary” aromas designed to mix and match. 

“This is quite an exciting development,” says Jas Brooks, a PhD candidate at the University of Chicago’s Human-Computer Integration Lab who has studied chemical interfaces and smell. “It’s tackling a core problem with smell in VR: How do we miniaturize this, make it not messy, and not use liquid?”

Artists have long attempted to bring scents into entertainment. In 1960, “Smell-O-Vision” made its first and only appearance with the film Scent of Mystery, which released odors during key plot points via air conditioning. But the effort bombed: during screenings, scents were either delayed or too faint to notice. 

These new interfaces are a notable development that could change how we experience VR. Olfaction is a powerful sense and a prerequisite for our mouths to detect flavor. The possibilities range from the obvious—sniffing a virtual flower field or inhaling VR food—to some less obvious applications. For example, perfumeries could test fragrances virtually.

Medically, scent-equipped VR could be helpful for people who have anosmia, or an inability to smell, according to Yu. Scents can also be therapeutic for patients with memory issues and might even help with mood. Yu told me he noticed he felt happier when he used the green tea scent in his tests. He realized that the smell was nostalgic: “When I was little, I’d have some chocolate with a green tea flavor,” he recalled. “I still remember peeling off the wrapper, and how I loved the smell.”   ... ' 

Morning Coffee Tech

An agriculture rea I worked in, some details here, will dig somewhat deeper.

Morning Coffee Tech  By Luana Ferreira in the BBC   Business reporter, Brazil

For an estimated one billion people around the world drinking coffee is a daily regime.

Yet what many coffee lovers might not know is that they are often drinking a brew made, at least in part, from Brazilian beans.

"Brazilian beans have popular characteristics, and are known for their body and sweetness," says Christiano Borges, boss of the country's largest grower, Ipanema Coffees.

"Therefore, many coffee blends in the world use our coffee as a base."

Brazil is far and away the world's largest grower of coffee beans. It accounts for more than one third of all global supplies, or 37% in 2020, to be exact. In second place is Vietnam with 17% of supplies.

Some 70% of Brazil's coffee plants are the highly-priced arabica species, used in fresh coffee. The remaining 30% are robusta, which is used primarily for instant coffee.

Brazil's largest coffee plantations stretch for miles on end

The problem for Brazil, and world coffee supplies in general, is that last year the country's annual crop plummeted by almost a quarter due to a drought across its main coffee growing region, which centres on the south-eastern states of Minas Gerais, São Paulo and Paraná., The knock-on affect has been a global reduction in coffee beans supplies, and a subsequent doubling in wholesale prices since this time last year.

To try to alleviate any future falls in production, Brazil's largest coffee producers are increasingly turning towards technology to help them successfully grow and process the best possible crop, both in terms of size and quality., One such firm, Okuyama, says it is now investing at least 10% of its revenues in technology. Based in Minas Gerais, it has coffee plantations covering 1,100 hectares (2,718 acres).

Its staff use a computer app called Cropwise Protector, which is made by Swiss-Chinese agricultural tech firm, Syngenta., Linked to ground sensors and satellite imagery, the tool gives the farm workers a visual analysis of the farm, or plantation, on a tablet device or laptop.

They can then quickly apply such things as drip-irrigation, or pest-control, to a very specific area that might need it, rather than a whole field or the entire farm.   ... ' 

Coffee Tech Overview

 Space I worked in for years, a brief  intro in the BBC

The tech helping to bring you your morning coffee,  By Luana Ferreira

Business reporter, BrazilFor an estimated one billion people around the world drinking coffee is a daily regime.

Yet what many coffee lovers might not know is that they are often drinking a brew made, at least in part, from Brazilian beans.

"Brazilian beans have popular characteristics, and are known for their body and sweetness," says Christiano Borges, boss of the country's largest grower, Ipanema Coffees.

"Therefore, many coffee blends in the world use our coffee as a base."

Brazil is far and away the world's largest grower of coffee beans. It accounts for more than one third of all global supplies, or 37% in 2020, to be exact. In second place is Vietnam with 17% of supplies.

Some 70% of Brazil's coffee plants are the highly-priced arabica species, used in fresh coffee. The remaining 30% are robusta, which is used primarily for instant coffee.  ... 

Miso Robotics at a Panera

Further goes automation of fast food and drink

Panera will test an AI coffee system from the makers of the Flippy burger bot   in Engadget

Miso Robotics' CookRight Coffee is designed to help restaurants run more efficiently.

Miso Robotics, the company that built a robot burger flipper in use at White Castle and a tortilla chip maker Chipotle is testing, has turned its attention to coffee. Its AI-powered CookRight Coffee system will monitor temperature, volume and time data. It will blend those metrics with predictive analytics to deliver cups of java. Miso suggests the system could help restaurants run more efficiently.

Panera Bread will be the first to test and evaluate CookRight Coffee before determining how to deploy the system. Miso says the product will nullify the need for workers to manually check the coffee urns and will brew fresh coffee at the right time. The system will also support Panera's Unlimited Sip Club plan, a subscription service that allows customers to drink as much coffee and tea as they want at the chain for $9 per month.

“When we announced the CookRight platform in 2021, we knew we could apply it to various stations at a restaurant as the product developed, and we saw an immediate need for it at the coffee station," Miso CEO Mike Bell said in a statement.   .... ' 

Making Pseudo Coffee

 I did technical analysis work for one of the world's largest coffee companies.  So this was interesting.  But I disagree that the environmental issues here are paramount.   They are minor.  Coffee can be grown with considerable environmental consideration.   I have tasted pseudo coffees and they they are less than ideal.  Black tea is not coffee.  And consider the farmers, which we did.   

Scientists Are on a Quest to Create the Perfect Cup of Coffee—Without the Beans   By Vanessa Bates Ramirez - in the Singularity Hub

Ahh, coffee. Is there anything more delicious, more satisfying? It’s always there when you need it, be it first thing in the morning or for a mid-afternoon pick-me-up. According to the Sustainable Coffee Challenge, global consumption of this vital brew is around 600 billion cups per year (I know—I would have guessed higher, too).

But as with many of the products we consume, there’s a cost beyond what we pay at the store. Producing coffee—like producing meat, or almonds, or corn, or pretty much anything—has an environmental cost, too.

It’s that cost that’s led innovative entrepreneurs to seek a more Earth-friendly way to produce everything from beef to milk to salmon. Now coffee is joining the club, with startups in the US and Europe experimenting with new ways to make crave-worthy coffee—sans any coffee beans.

One of these is Finland’s VTT Technical Research Centre. VTT uses a technique called cellular agriculture to grow its pseudo-coffee, filling bioreactors with cell cultures then adding nutrients that encourage growth. Heiko Rischer, VTT’s head of plant biotechnology, described one of the first cups brewed with his company’s product as tasting like something “in between a coffee and a black tea.”

If Finland seems like a surprising location for one of the first artificial coffees to be made—I personally would have guessed Italy, or maybe Spain—it makes sense when you put together a couple key factors. First, Nordic countries tend to be a few steps ahead of the rest of the world in terms of environmentalism ....'

Interacting with Computers Through Smell

In our innovation spaces we also looked at 'communication', and sales via smell and taste.  Since at the time we were makers of some very large coffee blends.    We worked with simulations of blends and how people interacted with them via taste and aroma.  We even tested the ability to 'smell' with computers to test blends and model consumer reaction.  And their reaction in virtual reality settings.

Interacting With Computers Through Smell  By Sandrine Ceurstemont, Commissioned by CACM Staff, October 7, 2021

We typically interact with computers and virtual environments using vision, hearing, and touch, but there is growing interest in also incorporating smell, to replicate more closely how we interact with the real world.

Odors could help people feel more present in virtual reality settings, for example, while smell could also play a role in how we make rapid decisions or recall memories when using computers.

"The question is how can we harness the power of smell in this increasingly digital world," says Marianna Obrist, professor of multisensory interfaces at University College London in the U.K.

There are still challenges to overcome before smell can be widely used as a mode of human-computer interaction, though. A better understanding of how it could impact different aspects of behavior in virtual environments, for example, is needed.

"What we are trying to do is to understand the temporal and spatial diffusion of scent in order to really understand the effect on the user," says Obrist.

In recent work, Obrist and her colleagues investigated whether smell could help direct a person's attention in a virtual reality environment. They conducted experiments in which participants were presented with an abundance of visual stimuli, and had to pick out those that looked like mint leaves. Either sounds, smells, or both were incorporated into the virtual scene, and were emitted from different positions  in the virtual environment, in order to learn whether they could help guide a person towards the mint leaf icons.

Participants were assessed based on the number of mint leaves they spotted and where they were located. The position of each person's head was tracked as they completed the task, to determine the direction they were looking and whether that matched up with the location from which a scent or sound was being emitted.

Obrist and her team found participants typically directed their attention to the source of a sound or smell. Furthermore, they seemed to explore the left side more thoroughly when a sensation was delivered from the left, compared to when it originated from the right side. The researchers think that could be because all the participants were from cultures that read from left to right. "That might have some effect which would need to be accounted for in the future," says Obrist.

They also found differences in how effectively people focused their attention when sound or smell were used on their own, compared to when both modalities were combined. "The integration of sound and smell definitely produced the best results," says Obrist. ... ' 

Coffee Analysis Using Pattern Recognition

Used to be in the coffee blend analysis and optimization space, so this was interesting.  Nicely done.  We did some similar things with classical optimization and statistical systems.  Below an intro, link takes you to more detail exploration and to the data and technical details.  Also a good example of this kind of pattern recognition problem.   See my 'Coffee' tag below for many mentions of our work and related research.

Comparing Coffee using Pattern Recognition

Exploring coffee similarities using cupping grades and flavors

By Robert McKeon Aloe   in Towards Data Science

After trying a variety of coffees from around the world, I have often wondered if coffee grades or flavors could tell me which coffees were similar to each other and which were different. I am particularly interested if such comparisons could be used to help determine the best blends by increasing my understanding of how coffees relate to each other. Luckily, I found some data to investigate just that question.

I have looked at two databases with coffee grades, and previously, I’ve used the CQI database to investigate similarities between coffees. I’m applying the same techniques here.

I amended one of the databases from Sweet Maria’s. I previously pulled their Q-scores, but they also had flavor ratings for each coffee. So I went back, and I pulled flavor ratings for all the beans. I ended up with a slightly larger database than previously at 407 coffees. ... "

IBM Traces Coffee Sourcing with Blockchain

Again, an area we worked in regarding coffee supply chain.   An increasingly common use of distributed ledger, and a means of sharing trust about sharing key parts of the supply chain.  Look for more coming out of this week's meetings.

IBM taps blockchain to make coffee sourcing traceable

sourcing coffee. It will enable a new app, dubbed “Thank My Farmer” to allow coffee drinkers to trace their coffee beans back to the original farmer.

The app will let the coffee consumer learn more about their coffee and even support the farmer who grew the beans. The whole idea is to bring traceability, efficiency, fairness, and communication across the coffee supply chain which supports the $200 billion industry. IBM will show the project at CES 2020, the big tech trade show this week in Las Vegas.... '

Small Coffee Farmers Seek Trust

And another example of Integrity-type usage  ....  Used to work in the coffee procurement and blending space, sometimes with small grower..   Might be an interesting place to look for small agricultural suppliers?

Coffee Farmers Bet on Blockchain to Boost Business   By Reuters 

The United Nations Food and Agriculture Organization said in a recent report that blockchain technology could potentially address challenges faced by smallholder coffee farmers by "reducing uncertainty and enabling trust among market players."

Blockchain facilitates shared access to data maintained by a computer network, and can rapidly trace the myriad parties involved in food production and distribution.

The Agriculture Alliance of the Caribbean (AACARI) has embarked on a blockchain project, which entails auditing by accredited professionals to ensure farmers comply with Global GAP (good agricultural practices) standards, and a digital marketplace where buyers can find information about the produce.

Vijay Kandy of AcreCX, the company building AACARI's blockchain platform, said farmers could bypass intermediaries and deal directly with buyers via the auditing process. Buyers would no longer need to rely on middlemen to ensure farmers are adhering to Global GAP.  ... 

McCormick and IBM Work on New Spice Blends

We also worked on blending for tastes, new and old.  Using AI and expert systems methods.  With multiple consumer preference, manufacturing and supply chain goals. Notably for years in the coffee industry, but also later in other food areas.   We even used classification methods to private blend coffee that would appeal best to consumers based on interaction in the store.  Later linking to sensory methods.  To create blend novelty based on blending options.    See more about this at the Label tag: Coffee below.   Look  forward to seeing this effort.

IBM and McCormick blend new seasonings with AI   By Kyle Wiggers in Venturebeat

On some future visit to your neighborhood supermarket, at least a few of the groceries you pick up for that night’s dinner party or the next day’s lunch will have been designed with artificial intelligence (AI) — or so thinks IBM. The Armonk, New York company today announced that it’s teaming up with McCormick & Company — the century-old purveyor of spices, seasoning, mixes, and condiments for industrial and home kitchens alike — to create new flavors and foods with machine learning.

The collaboration — which IBM says was four years in the making — will see McCormick & Company tap IBM’s Research AI for Product Composition tech for AI-derived insights, which IBM claims has already enabled the food company’s Consumer and Flavor Solutions divisions to discover new herb, extract, marinade, and stock flavor combinations up to 3 times faster. The recipe-predicting AI, drawing on McCormick’s proprietary “hundreds of millions” of data points across sensory science and flavor palettes, will fuel the launch of its forthcoming product family — One — which it expects will launch in mid-2019.  ... " 

See also in Fortune.

Examining Seasoning Research

Was for some time involved deeply in the manufacturing of CPG food.   Blending commonly used foods from agricultural commodities.   Also have been a cook for a long time.   So attuned to the use and usage trends in ingredients and spices.  Just recently noted the existence of a  Chinese 'Tainjin Seasoning Research Institute',  which makes a tomato paste sold at the local ethnic market.

China probes 'fake seasoning producing hub' near Tianjin
and more in the China seasoning realm. ... "

Smelling Moth Brains are Smarter

Its not news that biological neural networks are very different from those used in artificial neural  networks (ANN)  we still don't know how the former work.    The odor/aroma aspects were of interest when we looked at mechanisms of detecting and delivering smells and taste in coffee.

Why even a Moth’s Brain is Still Smarter than an AI   in Technology Review.
A neural network that simulates the way moths recognize odors also shows how they learn so much faster than machines.

One of the curious features of the deep neural networks behind machine learning is that they are surprisingly different from the neural networks in biological systems. While there are similarities, some critical machine-learning mechanisms have no analogue in the natural world, where learning seems to occur in a different way. .... " 

Voice Brewing Your Coffee

We were into the coffee business for a long time.  Blending, roasting, brewing, marketing and selling. Even using AI to find the best blends.   So the idea would have been fun and even useful in our labs to stage tests.  I am not enough of a coffee fiend to find this a generally useful  part of the smart home. But historically recall that 'smart' coffee pots were some of the earliest IoT ideas added to the Web.  Below is compatible with GHome and Alexa.

Smarter Coffee Brews your Java with Voice Commands
By Karl Utermohlen  ....  In DigitalTrends. .... 

Smelling with VR for Immersion

The CPG company I worked with for years used to have a big foods component and smell and aroma were major sensory components of products and product development.  So we paid much attention to understand how these sensory components might be detected, constructed and delivered.   In reality or virtually.  Coffee, for example, was much studied.    Here the claim is to produce a strong immersive component through smell.

The Sweet Smell Of VR With Vaqso VR

Tokyo start-up Vaqso VR develop a VR scent technology compatible with current VR headsets.

 By Rebecca Hills-Duty  in VRFocus Last updated Jul 3, 2017

The idea of ‘smell-o-vision’ has becomes something of a cultural joke in the past few decades since the idea was originally created for cinemas in the 1960s. Various versions of the technology have been in use since then, being used in theme park attractions and shops to create a suitable atmosphere for consumers. The idea is now making something of a comeback with the rise of virtual reality (VR).

The central concept of VR is that of immersion; the strength of VR lies in its ability to make a VR user truly feel like part of the virtual environment and not just a passive viewer. It is perhaps with this immersion in mind that the idea of adding scent begins to make sense. A Tokyo-based start-up named Vaqso VR has released a small smell-emitter that acts as an accessory for VR headsets. .... "

Algorithmic Gastronomy and Beyond

Fascinating look about how to morph recipes.  Might this be used to rewrite other process + ingredient kinds of decisions?  We were influenced in coffee blending and roasting decisions by recipe style approaches.  There is something here.

Deep Learning Algorithm Rewrites Traditional Recipes for New Regions, Ingredients
by Michael Byrne

 Algorithmic gastronomy is here.

Imagine your favorite go-to recipe mutated to conform to the traditional methods and ingredients of any number of diverse regional food cultures. Consider, say, lasagne, but a sort of lasagne that's instead a naturally occurring part of Japanese or Ethiopian cuisine. Not "fusion," but something deeper—a whole rewriting of what a lasagne even is according to the culinary traditions of some other place.

It's not necessarily an easy or natural thing to do, but a new machine learning algorithm developed by a team of French, American, and Japanese researchers offers an automated solution based on neural networks and large amounts of food data. The result, which is described in a paper published this month to the arXiv preprint server (via I Programmer), is a system that can take a given recipe and shift it into an alternative dietary style—sushi lasagne, say—as well as parse a recipe for its underlying style components.  .... " 

Computers Predicting Smell

An area we worked in for years when in the coffee business.  Were pitched a number of solutions to replace human abilities to taste and smell.  None were ever successful.   Is this finally the solution?  I continue to follow.

Computers That Can Smell
Teams of modelers compete to develop algorithms for estimating how people will perceive a particular odor from its molecular characteristics.
By Kerry Grens | May 1, 2017 .... " 

Putting Coffee Machines on the IOT

It has long been a challenge to connect coffee machines to the internet.   Something comfortable about making coffee available reliably at all times and letting us know it.   Even inspiring the worlds first webcam in 1991.  Now we are seeing it commercially, clearly a better way

 Nestlé picks Telefónica to build IoT for coffee machines by Alex Scroxton
Nestlé’s professional business services unit will incorporate internet of things technology into its coffee machines in pursuit of greater efficiency and customer satisfaction

International food and catering services supplier Nestlé has chosen Telefónica Business Solutions to provide a 50-country internet of things (IoT) communications network for its Nestlé Professional coffee business as part of a major digital transformation.  ... "  

Computers Sensing Odors

Another area we examined for possible classification of coffee blends, fragrances and for in store understanding of smell 'scapes' in retail spaces.   Investigation has been going on in this space for some time, but with incomplete precision.

It was thought that neural patterns might lead to results.  Some possible results:

In CACM:  " ...  Harvard University researchers have developed a machine-learning algorithm to train a computer to recognize the neural patterns associated with various scents, and to identify whether specific odors are present in a mix of smells.

The algorithm works like other pattern-recognition systems, only the patterns are the neural activation patterns of mice reacting to particular odors.

"Essentially, one odor causes a particular neural activation pattern, and another odor causes a different pattern," says Harvard professor Venkatesh Murthy.  ... " 

Electronic Tongue Tastes Wine

An area we explored on the coffee blending business.  Was still very primitive in capabilities at the time.  Some advances are seen here.  How can resulting data be connected to blending or manufacturing data?   In New Scientist.