Why do onions make you cry?
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Tyler Huey
- Posts: 1
- Joined: Sun Oct 14, 2007 2:22 pm
Why do onions make you cry?
My project is on lachrymatory factor which leads to increased tears when cutting an onion. What kind of experiment can I do to measure this? Thanks!
Lachrymatory factor causes you to cry when you cut into an onion. What kind of experiment can I do to illustrate this or how can I measure the strength of different types of onions?
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davidkallman
- Former Expert
- Posts: 675
- Joined: Thu Feb 03, 2005 3:38 pm
Re: Why do onions make you cry?
Hi Tyler,
Not addressing your question of experimental design, if you input "Why do onions make you cry?" to answers.com you'll get some useful background. Please see the WikiAnswers section, and ignore the Sponsored Link (which may be delicious, but it's an advertisement.)
Maybe some others can help on the experimental design.
Not addressing your question of experimental design, if you input "Why do onions make you cry?" to answers.com you'll get some useful background. Please see the WikiAnswers section, and ignore the Sponsored Link (which may be delicious, but it's an advertisement.)
Maybe some others can help on the experimental design.
Cheers!
Dave
Dave
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barretttomlinson
- Former Expert
- Posts: 932
- Joined: Wed Oct 03, 2007 12:24 am
A chemist would probably use a technique called gas or liquid chromatography to measure the amount of the odor causing compound.
You might be able to compare different onion types by using a serial dilution technique to find the relative concentrations which smell the same to you. you could use samples of the same amount of onion of each of your comparison types. You grind up each onion sample with the same amount of solvent(like water). Then take 1 drop of this sample and mix it with a few drops(like 9) of the same solvent(water). This is your first dilution. Take one drop of this and mix it with the same amount of water to make your second dilution sample. Keep doing this for several more dilutions. Do this for each of your onion samples. Now designate one onion as your standard and find a dilution where you can just detect the odor. Then you can try to find the dilution of the other onion samples that smells the same to you. This way you can determine how strong one onion is relative to the others.
I believe this technique is commonly used to test perfumes and food tastes. You need to be careful to rest your nose between trials as your sense of smell fatigues easily. You may also want to recruit several of your friends to help doing the comparison. Your results will be much more significant if several of you agree on the result.
This could be fun!
You might be able to compare different onion types by using a serial dilution technique to find the relative concentrations which smell the same to you. you could use samples of the same amount of onion of each of your comparison types. You grind up each onion sample with the same amount of solvent(like water). Then take 1 drop of this sample and mix it with a few drops(like 9) of the same solvent(water). This is your first dilution. Take one drop of this and mix it with the same amount of water to make your second dilution sample. Keep doing this for several more dilutions. Do this for each of your onion samples. Now designate one onion as your standard and find a dilution where you can just detect the odor. Then you can try to find the dilution of the other onion samples that smells the same to you. This way you can determine how strong one onion is relative to the others.
I believe this technique is commonly used to test perfumes and food tastes. You need to be careful to rest your nose between trials as your sense of smell fatigues easily. You may also want to recruit several of your friends to help doing the comparison. Your results will be much more significant if several of you agree on the result.
This could be fun!