Taste can be classified into five flavors that we sense, but how many odors can we smell? There are likely about 10 basic categories of odor, according to research published September 18th in the open access journal PLOS ONE by Jason Castro from Bates College, Chakra Chennubhotla from the University of Pittsburgh, and Arvind Ramanathan from Oak Ridge National Laboratory. The researchers used advanced statistical techniques to develop an approach for systematically describing smells.
Working with a standard set of data, Andrew Dravniek's 1985 Atlas of Odor Character Profiles, the researchers applied a mathematical method to simplify the olfactory information into coherent categories, similar to the way compressing a digital audio or image file reduces the file's size without, ideally, compromising its usefulness.
The team identified 10 basic odor qualities: fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, popcorn, lemon and two kinds of sickening odors: pungent and decayed. Senses such as hearing and vision can be discussed in terms that most people understand and that are tied to measurable physical phenomena. But the sense of smell, or olfaction, has thus far not lent itself to such a systematic understanding of what smells we perceive and how those perceptions relate to physical phenomena. "It's an open question how many fundamental types of odor qualities there are," says Castro. "This is in striking contrast to olfaction's 'sister sense,' taste, where we know that five basic qualities seem to organize sensations.
In ongoing work, the researchers are now approaching the problem from the other direction, applying the current research to a bank of chemical structures in an attempt to predict how a given chemical is going to smell. "That's something that nobody's really done with any kind of compelling accuracy," Castro says. "And obviously perfume companies, flavor and fragrance companies, are really interested in doing that well." He adds, "This study supports the idea that the world of smells is tightly structured, and organized by a handful of basic categories.
FAQs
Now, researchers have used mathematics to describe odors systematically and simplify them into 10 categories: fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, popcorn, lemon, pungent and decayed.
What are the 10 basic odors humans can smell? ›
The team identified 10 basic odor qualities: fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, popcorn, lemon and two kinds of sickening odors: pungent and decayed.
What are the 7 basic smells? ›
Methods: We adopted an in-silico approach to study key and common odorants features with seven fundamental odors (floral, fruity, minty, nutty, pungent, sweet, and woody).
How many basic smells can your nose detect? ›
What the the nose knows might as well be limitless, researchers suggest. The human nose can distinguish at least 1 trillion different odours, a resolution orders of magnitude beyond the previous estimate of just 10,000 scents, researchers report today in Science1.
What are the primary smells? ›
Any of the fundamental odours of which other odours are believed to be formed by combination, especially the six primary odours of Henning's prism: fragrant (like lavender or rose petals), ethereal (like ether or cleaning fluid), resinous (like resin or turpentine), spicy (like cinnamon or nutmeg), putrid (like faeces ...
What are the 10 things you can smell? ›
Scientists have classified odors into 10 basic categories: fragrant, woody/resinous, minty/peppermint, sweet, chemical, popcorn, lemon, fruity (non-citrus), pungent and decayed.
What scent can humans detect at 5/10 parts per trillion? ›
Human's can smell concentrations as low as 10 parts per trillion of Geosmin and MIB in water. The characteristic odor of soil was first investigated by Berthelot in 1891 (1). In 1965 the structure of the responsible compound geosmin was determined by Gerber (2).
What scent do squirrels hate? ›
Now that we know more about them, we'll discuss the scents they hate! The scents on this list are: Peppermint Oil, Capsaicin, Coffee Grounds, White Vinegar, Garlic, Cinnamon, Predator Urine, Irish Springs Soap, Dryer Sheets, and Rosemary.
What is the most loved scent? ›
From a list of ten unique scents, survey respondents from a variety of cultural backgrounds all ranked vanilla the most pleasant, reports Peter Dockrill for Science Alert. Researchers suggest there may be an evolutionary basis for the universal aroma preference, reports Peter Dockrill for Science Alert.
What smell do dogs hate the most? ›
For dogs, citrus scents are the enemy. Citrus scents like lemon, lime, oranges, and grapefruit–especially in high concentrations often found in household cleaners or essential oils–can cause irritation to your pup's respiratory tract, so keep any fresh citrus fruits out of your dog's reach. You know–just in case.
Peppermint oil — Essential plant oils like peppermint, rosemary, citronella, sage and lavender have strong botanical scents that rats dislike. One customer successfully repelled a rat by stuffing a peppermint oil soaked tissue into the rat hole chewed into the wall. The rat appeared to never come back.
What is the smelliest odor? ›
Thioacetone is regarded as one of the worst smelling compounds known to science. This organosulfur compound is known to induce vomiting, unconsciousness and nausea for up to a half-mile radius if exposed to air.
What are the six groups of odors? ›
Olfactory qualities
On the basis of the apparent similarities of perceived odour quality or confusions in naming, it was concluded that there were six main odour qualities: fruity, flowery, resinous, spicy, foul, and burned.
What are the 10 types of smell? ›
In doing this, Castro and this colleagues identified 10 basic odour qualities: fragrant, woody/resinous, fruity (non-citrus), chemical, minty/peppermint, sweet, popcorn, lemon and two kinds of sickening odours: pungent and decayed.
What smell can humans smell the best? ›
Scents that humans are particularly attuned to include chemical components in bananas, flowers, blood and sometimes pee. In 2013, Laska and colleagues tested the abilities of humans, mice and spider monkeys to detect urine odors found in common mouse predators.
How many different smells exist? ›
Humans can detect about one trillion different odors and have just as good a sense of smell as animals.
What is the most common smell in the world? ›
Vanilla may be the world's most popular scent, but you'll find these five scent categories anywhere you run off to.
What is categorization of smells? ›
As a consequence, there has been much disagreement over the validity of one categorization scheme versus another (Bowring, 2006): Revising Linnaeus's seven-category system of aromas (1756) (aromatic, fragrant, ambrosiac, alliaceous, hircine, foul, nauseous), Zwaardemaker offered a complex hierar- chy based on a nine- ...
How many odors are humans capable of smelling? ›
Humans can detect about one trillion different odors and have just as good a sense of smell as animals.
What are the six types of smells? ›
On the basis of the apparent similarities of perceived odour quality or confusions in naming, it was concluded that there were six main odour qualities: fruity, flowery, resinous, spicy, foul, and burned. Electrical activity can be detected with fine insulated wires inserted into the olfactory bulb.
Your scent is composed of the volatile organic compounds present in the gases emitted from your skin. These gases are the combination of sweat, oils and trace elements exuded from the glands in your skin.
What are the different body odor smells? ›
A person should also contact a doctor if their body odor suddenly smells different. A fruity smell could indicate diabetes due to having high levels of ketones in the bloodstream, while liver or kidney disease can often lead to a bleach- or ammonia-like smell due to a buildup of toxins in the body.
