How to dissolve avocado pits skins? Peeling hundreds of avo pits, help

February 23, 2020 2:39 AM

So for an ongoing project, I need to peel about 300 avocado pits every week. The end goal is to grow plants from the pits. Manual peeling is getting very tedious. Can you think of a way to dissolve/soften/loosen or otherwise gently remove the skins?

I get the pits weekly from partner restaurants. I then need to wash them to remove the last bits of flesh. I then soak them in water for a couple of days, then manually peel them off.

Here's the catch: the "naked" pits need to stay as unblemished as possible.

For the end product, the germinated pit stays very much visible above the soil.
Every scrape/nick in the pit will oxidize immediately and leave a black scar forever. So the manual peeling has to be done gently and carefully to leave as few marks as possible.

For this reason, peeling machines like those used for potatoes or carrots are right out.
I'm now thinking there might be some kind of chemistry/biology I can use to better soften/break down the skins, but that will leave the seeds intact and won't hinder the germinating process or the health of the future plants.

As far as I can tell the skins of the pits are very fibrous (cellulose?) but the pits are a completely different texture. Can you think of something I can use to help the process along? A specific pH? a common bacteria that will eat only the skins off?

I've tried blanching before and that just discolors the pits but doesn't help the skin removal.
If you've got biology or chemistry knowledge and have tips for me, I'm all ears!

posted by PardonMyFrench to Science & Nature (5 answers total)

It took me a couple of readings to figure out that you were talking about the seedcoat surrounding the pit, and not the outer leathery peel of the avocado that is in contact with the flesh.

If you're trying to germinate the pits, I would think that blanching might not be the best idea; it might kill the embryo. Have you tried letting them dry out a bit? This site says that they're often easier to peel when the seed has dried out for 48 hours.
posted by Johnny Assay at 6:53 AM on February 23, 2020 [1 favorite]

Instructions vary in their advice about whether to peel the skin off before sprouting them in water or not, so it seems to be optional. Have you tried just leaving the skins on until they've germinated? Presumably removing the remnants of the skin would be easier once the plant itself has split the skin.
posted by needs more cowbell at 9:46 AM on February 23, 2020 [1 favorite]

There's a trick I used recently for peeling the skins off hazelnuts-- blanching in a baking soda solution, which made the skins kind of soft and soggy so they rubbed off more easily. Blanching might kill the avocado pits, but to save the effort on 300 pits a week it might be worth experimenting with this, or maybe a non-heated version of the solution could work.
posted by music for skeletons at 10:24 AM on February 23, 2020

Response by poster: Thanks, Yes, i mean the seed coat indeed! They do need to come off because we engrave patterns on the "naked", exposed pit itself. I definitely have plenty to experiment with so keep the ideas coming!

From my personal experience, the germination goes 3-4 weeks faster if i remove the seed coat, and i've germinated a couple thousands so far...

I'm going to give the baking soda a trick to start with. Curious about any other tips!
posted by PardonMyFrench at 11:12 AM on February 23, 2020

I did some googling and found a paper that describes how to establish a colony of insects that live on avocado seeds. There was a picture of a big pile of avocado seeds with no seedcoat. The protocol just says to rub the seedcoat off with a rough paper towel. Have you tried something like that?
posted by Sublimity at 1:40 PM on February 23, 2020