Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum

Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum (http://www.molecularstation.com/forum/)
-   Botany Forum (http://www.molecularstation.com/forum/botany-forum/)
-   -   Why do ripe fruits - especially when canned - smell bad? (http://www.molecularstation.com/forum/botany-forum/25696-why-do-ripe-fruits-especially-when-canned-smell-bad.html)

Radium 06-10-2007 03:30 AM

Why do ripe fruits - especially when canned - smell bad?
 
Hi:

I notice that many fruits [excluding apples] emit foul odors when
ripe. What chemicals are responsible for this? I've done as much
research as I can on this but not gotten anywhere. This isn't a
homework assignment. I am asking these questions out of personal
interest.

I hate those odors. That why I like to eat apricots, peaches, and
similar fruits when they are sour, hard, and greenish. When sour,
hard, and greenish, most fruits smell pleasant. When they are too
ripe, they become excessively sweet, grossly-soft up and turn mucus-
yellow; this is when they start to stink.

What causes those immeasurably-foul odors?

It could not be putricine. Putricine smells like rotting flesh, which
is also a foul odor but totally different from that of ripe fruits. To
my nose, over-ripe fruits don't have a smell that even nearly
resembles rotting flesh. Both are equally bad odors, though.

Its also not ethylene - a chemical used to speed ripening. Ethylene
has a sweet pleasant smell to it. I have smelled it myself in a lab.
It's beautiful.

Butyric acid smells like stinky cheese [including Swiss], smelly feet,
sweaty shirts, dirty socks, neck-sweat, back sweat, filthy scalp and
unwashed hair. So it definitely isn't butyric acid. In fact, since
these foul odors occur after ripening [a process which uses up the
acids]; I doubt that any acid or acidic substance is responsible for
the foul odor of ripe fruits.

I notice the stink especially in canned fruits. Most fresh fruits
don't have as much of a strong stink even when ripe. However, canned
fruits [often dripping in syrup] have an unbearable stench to me.
Maybe it is something to do with the sugar? I don't know.

Why do canned ripe fruits stink more badly than fresh ripe fruits?

Also, it can't be ethanol. I like the smell of ethanol.

I've asked similar questions in science newsgroups, and they think I
have an olfactory perception disorder causing me to perceive odors
differently from other humans. I don't believe this at all.

I have tried tiresomely searching on google but there are no websites
that have an answer to my question.

Also, I've noticed that most ripe fruits do not have to be rotten in
order to give off the foul odors I sense. Simply being ripe causes the
odor.

Any assistance is greatly appreciated.

If this is out of your expertise would you please give me an idea of
who could answer my question?


Thanks,

Radium


Bill Penrose 06-10-2007 05:05 AM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 9, 7:30 pm, Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:

1. Employees of canning plants are notorious for defecating in canned
fruit.

2. Lots of vegetable matter decomposes into unpleasant things with
time or heat. I have a grapefruit tree near my window, and there are
days it makes me gag.

3. The odor of apples consists of about nine main ingredients. Other
fruits are even more complex. Many of these smell pretty bad on their
own, Some of them break down in the canning process, and the ones left
behind might stink pretty badly.

4. Things like sulfur dioxide might be added to preserve the color
during canning.

5. Fruit that is canned is often fruit that's too rotten to sell.

Dangerous Bill




Radium 06-10-2007 05:12 AM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 9, 10:05 pm, Bill Penrose <[Only registered and activated users can see links. Click Here To Register...]> wrote:

<snip fertilizer of sarcasm>

No offense but if you're going to answer, please do so with serious
responses. It doesn't take a rocket-scientist to figure out that
you're purposely goofing around.


Billy Rose 06-10-2007 05:25 AM

Why do ripe fruits - especially when canned - smell bad?
 
In article <1181452379.531948.46910@g37g2000prf.googlegroups. com>,
Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:


Seems like this question was posed a year ago and went nowhere. The only
difference I notice is that fresh is better.

- Billy
Coloribus gustibus non disputatum (mostly)

Radium 06-10-2007 05:39 AM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 9, 10:25 pm, Billy Rose <[Only registered and activated users can see links. Click Here To Register...]> wrote:


Okay. What chemicals are responsible for the foul smell of ripe
fruits? Why is the odor even worse if the fruits are canned?


Omelet 06-10-2007 06:46 AM

Why do ripe fruits - especially when canned - smell bad?
 
In article <1181446222.307022.185680@a26g2000pre.googlegroups .com>,
Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:


<snipped troll>

You do this every year...
Last time it was on rec.food.cooking.

Get a life!
--
Peace, Om

Remove _ to validate e-mails.

"My mother never saw the irony in calling me a Son of a bitch" -- Jack Nicholson

Radium 06-10-2007 03:46 PM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 9, 11:46 pm, Omelet <[Only registered and activated users can see links. Click Here To Register...]> wrote:


Excuse me. The questions I've asked about ripe fruits are not trolls.
I asking a serious question in a crosspost to all relevant newsgroups.
WTF does everyone think I am a spammer looking for attention?!

I did ask this question about ripe fruits last year. All I got was
nonsense responses -- some blaming it on my "genes" or nervous system.
Both which I know to be totally wrong.

Please abide by my humble request to answer my questions with serious,
rational answers [please, please, please]:

What chemicals are responsible for the foul smell of ripe fruits? Why
is the odor even worse if the fruits are canned?

I don't know what the answer is, but I do know that it is *not*
putricine, ethylene, butyric acid [or any acid/acidic substance for
that matter], ethanol, chemicals resulting from fungus, or chemicals
resulting from decomposition. In addition, the answer is nothing close
to what "Bill Penrose" [the goofball] claimed. I am guessing it is
most likely an organic substance [i.e. a compound containing carbon
and hydrogen] but none of those described above.

Please obey my desperate requests to answer rationally and as
correctly as you can. Please also keep out the jokes, humor, and off-
topic crap. It's not amusing.


Omelet 06-10-2007 04:09 PM

Why do ripe fruits - especially when canned - smell bad?
 
In article <1181490399.194645.201930@g37g2000prf.googlegroups .com>,
Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:


Okay, two questions.

Have you tried googling, and, why do you care?
If the fruit smells/tastes foul to you, just don't eat it!

The vast majority of us don't seem to have your problem so the genetic
issue is definitely a real partial reason. Your denial of that is
counterproductive.

And, if you do find out what you are looking for, what are you going to
do about it?

Okay, so that was 3 questions. ;-)

I don't find canned fruit to be foul odored or tasting. I love it. I
also prefer ripe fruit to green. To me, under-ripe fruit is sour and has
a crappy texture. Every single person that I am personally aquainted
with is in agreement.

Give me a half-melted peach any day over a rock hard one!

Since you seem to be over-sensitive, you might be able to make some
money as a scientific guinea pig.

You, my dear, are NOT NORMAL!
--
Peace, Om

Remove _ to validate e-mails.

"My mother never saw the irony in calling me a Son of a bitch" -- Jack Nicholson

Bill Penrose 06-10-2007 04:38 PM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 9, 10:12 pm, Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:

Then omit number one. The rest are reasonable explanations, plus the
possibility that you may have one of the many forms of anosmia.
Usually it is just age, but sometimes changes in the sense of smell
are the first symptoms of a brain tumor.

Have a nice day.

DB


Bill Penrose 06-10-2007 04:49 PM

Why do ripe fruits - especially when canned - smell bad?
 
On Jun 10, 8:46 am, Radium <[Only registered and activated users can see links. Click Here To Register...]> wrote:

You mean you *know* the answer? Then why the question?

When fruits ripen, one of several mechanisms of autolysis set in.
Enzymes are cut loose that begin the breaking down process of the
fruit. In most berries, the 'purpose' is to attract birds or other
animals that will eat the berries and distribute the seeds. Many
fruits work this way, too. Bananas are a good example. They don't turn
black because of bacteria or mold, but because enzymes start breaking
down the fruit from inside.

Only later do bacteria, molds, and yeasts get in the picture. Some
berries become so fermented that birds have been observed to get
drunk.

The products of autolysis include alcohols and esters, but they're
different for every kind of fruit, depending on the enzymes present.

Now what happens in canning? The enzymes would be killed by the heat,
so any breakdown would have to be nonenzymatic, ie, esters decomposing
to alcohols and acids, etc. Sulfur compounds to smaller and more
volatile sulfur compounds, etc.

By the way, my mother once worked in a fruit packing plant. She would
never eat canned fruits or vegetables again because of the practices
she saw there.

Okay, there's your answer. It is also true that food companies go to
some lengths to prevent these processes, so don't rule out the brain
tumor hypothesis either.

DB




All times are GMT. The time now is 03:06 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 - 2012 Molecular Station | All Rights Reserved

Page generated in 0.09773 seconds with 11 queries