40 lbs of Juicy Fruit Stink

July 11, 2011 1:10 AM

I recently bought an enormous jackfruit (40lb) which needs a few days of ripening (the price was right). It has a few small mold spots. What can I do to slow down the mold while it's ripening so it doesn't go bad, while still leaving it edible?

Some thoughts:
- 70% Ethanol spray to kill anything on the outside
- Use a portable steamer
- Sunlight (UV?)

I am not about to flame-sterilize a fruit larger than my torso. Any ideas?

posted by benzenedream to food & drink (9 answers total)

You could go to a homebrew shop and get some iodophor. It can also be found as a farm store under the name cow teat dip. It should sterilize the outside and not do much else. I don't think it should do anything to the rest of the fruit, but again ymmv.
posted by koolkat at 1:15 AM on July 11, 2011

Vinegar inhibits many kinds of fungal growth (that is, if you're sure it's mold, and not some other sort of decomposition).
posted by Bardolph at 1:25 AM on July 11, 2011

perhaps too outside of the box, but...ozone treatment?
posted by trevyn at 2:00 AM on July 11, 2011

I was going to chime in with the vinegar suggestion.
posted by From Bklyn at 4:16 AM on July 11, 2011

The vinegar might be a bad idea. I'm not familiar with jackfruit specifically, but fruit is usually acidic, which means any mold eating it is going to tolerate that. Plus, vinegar doesn't usually kill mold.

Without your describing the mold (grey, blue, penetrating the rind?), it looks like the way to kill mold is a baking soda solution, or if it's really bad, a dilute bleach solution. If it's really really bad, you could try excising the mold spot, surface sterilizing with baking soda, and sealing with hot wax but I wouldn't do that except as a last resort. Make sure you keep the fruit dry with plenty of airflow.

The catch is going to be that if you've got a mold with hyphae, a surface sterilization won't kill all of it and it can change the flavor of the fruit. It might slow it down if you apply it faithfully once or twice a day, but then again, it might not.

I really wouldn't want it throwing spores around my kitchen. Once you get spores in an area, other things (such as strawberries and grapes) will rot faster than they should.

Ethanol is inhibited by organic material and is not traditionally used on food. UV light from sun may not be powerful enough and UV light from a handheld source may not penetrate to the hyphae. A steamer will leave water in the crevices which will cool and encourage mold growth. You want to leave a residue of something, which is why the baking soda or bleach is a better solution.
posted by arabelladragon at 4:41 AM on July 11, 2011 [2 favorites]

If this was a fruit ripening on my counter (like a tomato), I'd probably just cut the moldy spots out and then wash the fruit to make sure that spores weren't hanging around to make new spots. A topical treatment's probably not going to do much except kill the mold cells on the top unless it's some sort of nasty penetrating chemical that you shouldn't eat.

This doesn't seem like it would be any different despite its size-- you're going to have to cut it in a few days anyway to eat it. Cut away the affected areas and excise a bit more than you have to to make sure that you got all the mycelia and keep on top of any new spots. Optionally, scrub the rest with actual soap (Ivory, Dr. Bronner's etc) and water with clean cloth/paper towels.

The moldy spots are probably going to be permeable to other microbes, if you're worried about cutting for the sake of not making the interior vulnerable. You could pack the wounds with cornmeal (which is used by organic gardeners as an antifungal) and cover them with plastic wrap. The cornmeal would also act as a desiccant and collect any condensation under the plastic.
posted by Mayor Curley at 6:20 AM on July 11, 2011

Instead of slowing down the mold, you could speed up the ripening process by making a loosely-sealed paper bag container for it. Paper bags trap the ethylene that allows fruit to ripen. My grandma always tells me to put apples inside along with whatever I'm ripening, which may be because they release more ethylene, but who knows.
posted by quiet coyote at 8:34 AM on July 11, 2011

Wikipedia informs me that there are ways to prepare the fruit for eating before it is fully ripe. Is it too unripe for even those preparations?

Barring that, I would not wash the fruit- washing/water can speed up the mold. I would try vinegar or peroxide just on the bad spots. Then you could put it in a big brown bag or wrap it loselywith brown butcher paper with a banana. The banana emits the ripening gas that others have mentioned (understand that banana emits more than any other fruit)..
posted by LyndsayMW at 10:01 PM on July 11, 2011

Well, I stayed away from chemical treatment. I just cut off the mold on the stem, then kept it under a range hood to make sure it stayed dry after a light dusting of baking soda. I figured it's a big enough fruit that the internal ethylene will ripen it even if the external ethylene gets swept away.

It seems to have worked -- the fungus spots haven't gotten any bigger and the fruit is getting ripe. It should be ready in another two days to be cut up and the fruit extracted. Thanks for all the suggestions! I'll have to keep some iodophor handy for future kitchen sterilizations.
posted by benzenedream at 3:45 PM on July 15, 2011