How Do Perfumes Smell so Nice?

Описание: A short video explaining what perfumes are, what compounds make up perfumes, and how we smell them. I hope that you guys all learned something new from this video :)

Timestamps:
00:00 Intro
00:21 What are perfumes?
00:50 What are the aroma compounds?
02:08 How do we smell the perfume?
02:48 Summary

Music:    • K/DA Beats for Lo-fi Legends | Legends of ...  
Song title: K/DA Beats for Lo-fi Legends
Artist: Legends of Runeterra
Courtesy of Riot Games: https://www.leagueoflegends.com/en-gb...

Sources:
https://www.canr.msu.edu/news/fragran...
https://www.thoughtco.com/aroma-compo...
https://dermnetnz.org/topics/fragranc...
https://science.howstuffworks.com/per...
https://lifestyle.howstuffworks.com/s...
https://www.ucl.ac.uk/news/2013/jan/s...

Transcript:
Smell is one of the most underrated senses that we have, as it alerts us of our rotten eggs and influences our social interactions. Being such an important sense, humanity has been using perfumes for the past 5,000 years since ceremonies in Ancient Egypt. So in this video, we will explore what perfumes are, the molecules behind some of the scents, and how we smell them.

First, let’s establish fragrances, which are organic substances that produce a distinct odour. And so we can think of perfumes as a liquid fragrant, which contains a mixture of water, alcohol, and aroma compounds, which are compounds that have a smell. Those compounds in perfumes are usually derived from essential oils, flowers, synthetic materials, and much more. The concentration of those compounds range from 20-30% in parfums, to 1-3% in fraiche. The commonly used cologne is only at 2-4%!

So what are those aroma compounds exactly? The most common ones are terpenes and esters, which give off a wide variety of fresh floral and fruity scents. Those compounds are derived from the plants associated with the scents, as an example, citral comes from lemongrass and produces a lemon-y scent. Oh, and quick bonus fact, odours refer to any smell, while scents refer to only pleasant smells. Aldehydes give off a grassy and cocoa scent, while ketones give off a fresh food-y scent. Though if we are looking for some more nasty odours, say for a fart spray, we can add amines, which are derived from rotting meat and feces, reproducing their odours. Most perfumes are layered, so we get a few different scents depending on how long we have applied the perfume for. The top note is the lightest scent that we smell first, lasting only around 10-15 minutes. The fresh and uplifting citrus scents, like aldehydes and ketones mentioned earlier, are often found in top notes. Next, we have the heart note, which is the main scent of the perfume that kicks in after the top note evaporates away. It lasts for around 2-3 hours, and often contains the romantic floral scents. Lastly, we have base notes, which lasts for up to 24 hours and provides depth to the fragrance, often including the rich oriental and warm woody scents.

So now, how do we even smell those scents? According to vibration theory, differently shaped compounds emit different odours because of the way they vibrate. So, as those mixtures evaporate, the aroma compounds reach our noses, with each unique compound vibrating at a specific frequency. The olfactory nerves then convert them into electrical signals for our brain to determine what scent we just smelled. So, with the three notes together, perfumes are able to establish complex scents that vary widely depending on the aroma compounds used. Since each compound evaporates at different rates, the mastery of making perfume lies in knowing which compounds to combine together to make the desired scent.


And there we have it! Perfumes are liquid fragrances with different concentrations of aroma compounds. There are many different compounds that give us different scents, which are determined by the compounds’ shape. Knowing which compounds to use and how long it takes for them to evaporate is the key to crafting the perfect perfume using chemistry. I hope that y’all have learned something interesting today, thank you for watching, and stay hydrated!

#perfume #chemistry #science