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General Science => General Science => Topic started by: Yunfeng Li on 27/08/2009 11:30:02

Title: Does fruit absorb the alcohol in punch?
Post by: Yunfeng Li on 27/08/2009 11:30:02
Yunfeng Li  asked the Naked Scientists:
   
Hi Chris,

I have been an avid listener (http://www.thenakedscientists.com/HTML/podcasts/) for several years now and I find your show as enjoyable as ever. My question is regarding the alcohol content in a punch. It is commonly known that you will get more drunk if you eat the fruit.
Does the fruit have higher alcohol content than the punch and if so, what is the reason for it?

Thanks for the show (http://www.thenakedscientists.com/HTML/podcasts/) and keep up the good work.

Yunfeng Li
Shanghai

What do you think?
Title: Does fruit absorb the alcohol in punch?
Post by: glovesforfoxes on 27/08/2009 16:33:49
maybe it does, maybe it doesn't. it probably does soak up alcohol (i can see no reason why it shouldn't!). if you eat the fruit, though, aren't you consuming more alcohol than if you don't, and will get more drunk if you do so?
Title: Does fruit absorb the alcohol in punch?
Post by: Nizzle on 28/08/2009 14:28:55
I know from empirical study that fruit absorbs alcohol.
I had a friend at university that never drunk any alcohol out of principle.
However, one day, we made some sangria at our dorm for a party and at the party she was drinking coke or water, but eating the fruit from some one's sangria.

I dragged her to her room at 4am...
Title: Does fruit absorb the alcohol in punch?
Post by: AllenG on 29/08/2009 07:15:19
Osmosis (http://en.wikipedia.org/wiki/Osmosis).  The fruit's membranes are permeable to  alcohol so it will pass from an area of high concentration to an area of low concentration.

Title: Does fruit absorb the alcohol in punch?
Post by: Bored chemist on 29/08/2009 13:49:44
Strictly, since the question was "Does the fruit have higher alcohol content than the punch" the answer is no.
Given a long enough time the concentration would be the same in the fruit and the punch.
For someone unused to alcohol that could be enough to affect them.

Title: Does fruit absorb the alcohol in punch?
Post by: lyner on 30/08/2009 16:57:07
Is it something to do with the fact that the only time that fruity punches are served is when there are a lot of 'non drinkers' involved? I have never been to an event with seasoned drinkers alone, which involved 'fruit punch'
Auntie Millie gets high on a strong cup of tea.
We may not have a truly fair test here.
Title: Does fruit absorb the alcohol in punch?
Post by: Yunfeng Li on 31/08/2009 09:50:48
People seem to agree that fruit does contain alcohol, which it does. People also consent that the alcohol concentration is the same inside the fruit cells as the punch outside. But is it possible that alcohol might be caught in the lipid membrane layer and thus accumulate there to a higher level than the other parts. Considering that the solubility of alcohol in either fat or water is very high, the importance of a lipid layer might not be significant but theoretically, it should be taken into consideration.
Title: Does fruit absorb the alcohol in punch?
Post by: lyner on 31/08/2009 10:12:17
A double blind test could be done. One punch with soaked fruit and one with 'just added' fruit could be served and the results could be measured / observed.
Title: Does fruit absorb the alcohol in punch?
Post by: Nizzle on 31/08/2009 10:44:03
Quote from: Yunfeng Li  on 31/08/2009 09:50:48
People seem to agree that fruit does contain alcohol, which it does. People also consent that the alcohol concentration is the same inside the fruit cells as the punch outside. But is it possible that alcohol might be caught in the lipid membrane layer and thus accumulate there to a higher level than the other parts. Considering that the solubility of alcohol in either fat or water is very high, the importance of a lipid layer might not be significant but theoretically, it should be taken into consideration.

Since alcohol is polar, it's solubility in water is much higher than in lipids.
Normally you would expect a polar molecule to have great difficulty in crossing a lipid membrane, but ethanol, the alcohol we speak of here, is a very small molecule, which allows it to cross the lipid membrane much easier than large polar molecules.

Now, as Bored Chemist already said: when given enough time, there will be an equilibrium of alcohol concentration in the fruit and in the punch. The alcohol will not be 'caught' in the fruit cells, because infusion and effusion rates are the same over the lipid membrane. And alcohol will not be 'caught' in the membrane for sure, due to it's polarity.
Title: Does fruit absorb the alcohol in punch?
Post by: Variola on 31/08/2009 23:09:25
Quote
Since alcohol is polar, it's solubility in water is much higher than in lipids.
Normally you would expect a polar molecule to have great difficulty in crossing a lipid membrane, but ethanol, the alcohol we speak of here, is a very small molecule, which allows it to cross the lipid membrane much easier than large polar molecules.

Now, as Bored Chemist already said: when given enough time, there will be an equilibrium of alcohol concentration in the fruit and in the punch. The alcohol will not be 'caught' in the fruit cells, because infusion and effusion rates are the same over the lipid membrane. And alcohol will not be 'caught' in the membrane for sure, due to it's polarity.


Do you get out much Nizzle???   [V] [;)]
Title: Does fruit absorb the alcohol in punch?
Post by: Nizzle on 01/09/2009 05:27:59
Sure I do Variola,

It's a bartender that told me all about fruit and punch and alcohol polarity [;)]