Sciencemadness Discussion Board

Chemistery experiment on fruits

heasliponline01 - 13-4-2014 at 05:55

If I add alcohol, can I find out if the fruits I am buying are contaminated with chemical insecticides?
I just saw a tv show and I always actually wondered about how do the fruits last so long in the market, compared to the ones from my grandma's tree, and I am almoust convinced that even if I wash up the fruits, there would be still some poisoning chemical left. Any advices?

Fantasma4500 - 13-4-2014 at 06:46

there is something with ethene forming in fruits that makes them rot, supposing there are things added to the fruits that eliminates the ethene thus making it last longer

GMO should also be considered

Texium - 13-4-2014 at 06:55

They often pack bananas with potassium permanganate during shipping to absorb the ethylene that they produce, keeping them from ripening. Then they give the bananas a heavy dose of ethylene to induce ripening just before delivery to the supermarkets.

Etaoin Shrdlu - 13-4-2014 at 07:18

Quote: Originally posted by heasliponline01  
If I add alcohol, can I find out if the fruits I am buying are contaminated with chemical insecticides?

No. You could buy organic if you're worried.

that's obvious

blazeriggins127 - 13-4-2014 at 07:19

I think is a very good topic and if everybody knew how to do this experiment at home they would be amazed by what we intake in our bodies.. It is obvious that there is an amount of insecticides left in the fruits, but some of those chemical are deadly and it is good to do a basic experiments with fruits bought from different stores, so you could find out where are healthier alternatives in fruits and vegetables. The process is not easy to do at home thou, espoecially for people who are not really into chemistry, but there are various solvents you could use such as chloroform, acetone, acetonitrile and methanol.

MrHomeScientist - 14-4-2014 at 06:54

While this would certainly make an interesting experiment or science fair project, to me it sounds just a bit too paranoid. I, and most everyone I know, has been eating fruit all their lives and nobody's dropped dead from biting into an apple containing minute traces "boogeyman chemicals."

confused - 14-4-2014 at 07:16

if you want to do it, i suggest rinsing the fruits in a solvent (ethanol+water mix .etc) and concentrating it, analysis could be a problem, TLC might work, not very sure

CHRIS25 - 14-4-2014 at 07:40

Quote: Originally posted by MrHomeScientist  
While this would certainly make an interesting experiment or science fair project, to me it sounds just a bit too paranoid. I, and most everyone I know, has been eating fruit all their lives and nobody's dropped dead from biting into an apple containing minute traces "boogeyman chemicals."

Well I certainly do not have any knowledge in this field, but there is one recurring fact that slips through many a scientific program or journal that I read and that is this: Some chemicals can take years and years to show any effects, on top of this there are those other "boogyman" things that compound the whole problem when the human body is synthesizing a multitude of chemicals together, mixed, that have effects not even understood today, and one more fact, it can even take a generation for the build up of such things which will have no effect on the person digesting it, but on their children's DNA that then gets passed on. The world is awash with medical problems, I am certain our food has and does play a significant role. Having said that I am eating a banana right now:D

Tsjerk - 14-4-2014 at 07:48

Could you explain how the experiment is preformed?

My first thoughts are that the methods they use to keep the fruit fresh (not ripe) for a longer period of time are, as mentioned before, by keeping ethylene out.

A quite famous experiment is to have fruit from the exact same source in four conditions.

1. a ventilated environment, not touching,
2. a ventilated environment, touching,
3. a not ventilated environment, not touching,
4. a not ventilated environment, touching.

In conditions 2, 3 and 4 the fruit will decay faster.

An important control is (1) the addition of ethylene to a single piece of fruit in a not ventilated environment and the same piece of fruit (2) in the same environment without addition of ethylene.

In the control environments, number 1 will decay, while number 2 won't.

Fruits want to mature at the same time to make their distribution by animals more likely (more change of attracting animals together than by themselves). They do this by producing ethylene when becoming ripe, and becoming ripe when sensing ethylene, a positive feedback loop.

Because of these experiments one could conclude the altering of the natural process is not harmful to the animal eating the fruit, as nothing is added. The fruit won't change in any way by capturing the ethylene, even when ethylene is added to make the fruit ripen afterwards.

I'm really curious about the experiment you saw on TV though.



[Edited on 14-4-2014 by Tsjerk]