On Jun 1, 3:26*pm, Hipupchuck > wrote:
> What's that black mold between onion skins? Is it still safe to eat?

This black mold belongs to the genus Aspergillus of fungi and is known
as the Aspergillus black mold. If your fingers come in contact with
it, a good washing with soap and water will do the trick. However,
onions carrying this mold are often bruised or damaged even up to
their very core, so to be safe, you should simply throw away those
that are contaminated.

Aspergillus black mold in onions grows in warm climates such as the
farms in the southern states. Farmers and quality inspectors rarely
know about this type of mold growth as it is hidden between the
onion's skins, and sometimes there are no visible signs of damage from
the outside. Although mold is known to proliferate in humid
conditions, Aspergillus in onions have also been common in extremely
hot desert-like places where onions are cultivated.

A. niger is less likely to cause human illnesses than other
Aspergillus species, but it has been found to produce an illness known
as aspergillosis when large amounts of its spores are inhaled. Some
symptoms of aspergillosis a cough, chest pains, fever, and
difficulty in breathing.

Severe cases may involve shock, chills, delirium, coughing up of
blood, and blood clots. It's also possible that the mold finds its way
into your other organs and destroy healthy cells there, causing
breathing difficulties, liver failure, or kidney failure.

Where Aspergillus black mold originates

The mold can start its attack even as the bulbs are still in the
fields. They can also multiply during storage and can start from a
simple bruising of the bulb. This is why it is important to handle the
bulbs carefully during harvesting and processing - to keep damage to a
minimum.

Some people simply wash away the offensive Aspergillus Black Mold
until the onion is seemingly clean when inspected. However, tiny
spores left behind are too microscopic to be seen. If you know the
health problems associated with the ingestion of black mold, you'll
never think twice about throwing contaminated onions away.

If you are cultivating your own onions, always store them in a warm
and dry place for curing, such as on wire baskets on your kitchen
counter or hanging from your durty kitchen ceiling, and in a cool but
dry place when storing.

As a rule of thumb, the temperature where you would be storing your
onions should be in the range of 32 up to 40 degrees Fahrenheit. Any
warmer would cause spoilage, and any increase in humidity would just
encourage the growth of Aspergillus black mold.

Farmers have tried several fungicides to control the growth of this
mold on onions, but no particular fungicide has been found to be
effective. And as there's no surefire way to tell whether your onions
are contaminated, you'll just have to be risking this possibility for
now.

You can also find more info on Black Mold. Blackmoldbliss.com is a
comprehensive resource which provide information about Blackmold.

On Mon, 1 Jun 2009 15:36:33 -0700 (PDT), Chemo the Clown
> wrote:

>Some people simply wash away the offensive Aspergillus Black Mold
>until the onion is seemingly clean when inspected. However, tiny
>spores left behind are too microscopic to be seen. If you know the
>health problems associated with the ingestion of black mold, you'll
>never think twice about throwing contaminated onions away.

That was very informative. I'll think twice next time I see it. I
usually just take off the offending layer and don't worry about it.

--
I love cooking with wine.
Sometimes I even put it in the food.

On Jun 1, 8:55*pm, Hipupchuck > wrote:
> Chemo the Clown wrote:

> > As a rule of thumb, the temperature where you would be storing your
> > onions should be in the range of 32 up to 40 degrees Fahrenheit. Any
> > warmer would cause spoilage, and any increase in humidity would just
> > encourage the growth of Aspergillus black mold.
>
> This stuff appeared on half an onion that I had in a sandwich bag in the
> fridge after only a couple days. I believe it's about 42 degrees in there..

For safety's sake, and to keep your cold foods longer, fridge temp
should be in the upper 30'sF.

I've been removing the layers with mold on them, and rinsing
everything well afterwards, with no ill effects after cooking. If you
have someone in your household or guests with less than robust immune
systems, you might be better off tossing the whole bulb.

maxine in ri