In article ,
"Anth" wrote:
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In article ,
Anth wrote:
I've noticed that when I've left my pineapples for a while and when I've
peeled them to see if they are fit to eat, I've noticed that they tend to
go
bad from the core outwards.
The core becomes dark coloured while the outer fruit has not?
If this is true, then has anyone got an explanation for this?

This is a strange question for sci.med. sci.bio.botany would be a
better choice, so I've added it.

The answer, however, is simple. The fruit isn't rotting, it's
ripening. Ripening involves the breakdown of pectins and other
structural materials and the conversion of starches to sugar.
Pineapples also produce bromelain, a protein-digesting enzyme, to
discourage herbivores from eating the fruit before the seeds are
mature, so you'll note that not only are these discolored fruits much
sweeter and more aromatic, they also won't make your mouth burn as
much. The fruit ripens from the inside out. If you let it continue to
ripen, the outer parts will get darker, softer, sweeter and more
aromatic, but the core may also be attacked by yeasts and molds which
cause rotting.

Have you got any info on the mechanism that makes them ripen from the inside
out?
(I don't always throw the pineapples away when they darken - only sometimes,
I do find them a lot sweeter that way)

So where are the seeds? Pineapples are sterile triploids and don't
make seeds. The fruits of their normal relatives have a very hard,
pea-sized seed in each of the segments, and have probably evolved to
have their seeds distibuted by a herbivore large enough to swallow the
seeds whole and break down the seed coat in their digestive tracts.
Such herbivores are attracted by a fragrant, softened, sweet fruit in
which the bromelain feeding deterrent has broken down.

People in temperate regions are accustomed to eat tropical fruits in an
immature state, because they are picked immature and shipped in that
condition. If you talk to people from tropical countries, they'll tell
you that they eat fruit ripe, when it's too soft to ship any distance
and very rich in flavour. Many fruits don't ripen well off the plant,
and people who've had the real thing feel the same way about the
tropical fruits we get in the north as anyone who's eaten a real
field-grown picked-ripe tomato feels about the rock-hard ones in the
supermarket in the winter that are almost indistinguishable in flavour
from head lettuce.

Interesting post - I should test other fruits to see if they ripen from the
inside out.

At least some cultivars of mangoes do this. It may well be a general
feature of fruit ripening, but only really obvious in those with a
"core" (pineapples) or with a central seed, and a fairly thick layer
of flesh around the centre. Even if those with a relatively thin
layer of flesh (e.g. litchi, longan, rambutan) do the same thing, it's
probably not all that noticeable when eaten.


Cheers, Phred.

--
LID

"Phred" wrote in message
...
In article ,
"Anth" wrote:
wrote in message
...
In article ,
Anth wrote:
I've noticed that when I've left my pineapples for a while and when
I've
peeled them to see if they are fit to eat, I've noticed that they tend
to




While living in Costa Rica my maid would keep over ripened pineapple to make
chicha(a type of fruit wine). It was delicious and would quickly put you on
your butt.

There was also another one made from drippings from the stalk of the Coyol{a
type of coconut). Personally, I found the pre-fermented juice tasted
terrific.

Chuck


--
LID