In this kemp layer we will be extracting piperine from peppercorns, white pepper is the best

to use because it usually contains a higher percentage of piperine and less

resin but we are going to use black pepper we're starting with 100 grams of

black peppercorns actually these are known as Asian red peppercorns and have

a slightly brown color our first job is to grind these up as fine as possible we

used a coffee grinder to first grind the peppercorns into a powder then placed

this through a fine sieve

in order to get the really fine portion of the powder like this be careful when

dealing with the fine powder because it easily gets everywhere and although it

has an amazing aroma it is not too great when you get it in your eyes or nose the

residual coarse pepper is collected placed back into the grinder and then

passed through the sieve again the last bit of coarse pepper is just added to

the mix

sure here's what we ended up with after the grinding and sieving process now you

need to find a large container that will easily hold five to six hundred mils of

liquid it also needs to be microwavable i.e. having no metal parts we used this

large wide neck conical flask using a funnel transfer the finely ground pepper

into the container

then prepare 150 mils of absolute ethanol our ethanol is slightly yellow as

it was previously recycled from another pepper extraction apparently isopropyl

alcohol also works in this process but we've not tried this ourselves add the

alcohol to the container with the pepper and slosh it around to form a slurry of

pepper

yeah

yeah

yeah

stick to the sides but this is okay now for our microwave extraction we used a

regular kitchen microwave set on a 400 watt power level the reason for the

large container is so that if the alcohol boils it will be contained

safely start heating the mixture but be careful not to overheat and boil the

mixture you will probably get a little bit of bumping in the container as the

mixture heats up but nothing too serious

when the mixture boils allow to cool and then repeat the process several times

we estimate we got about four to five minutes total microwave heating exposure

time this is what the mixture looks like when it's been thoroughly cooked allow

this to cool down a bit

then we filter the mixture

we use the

switch your computerThank you!

because it's cleaner but a normal filter paper will work as well. You can see the

nice yellow-brown color of the alcoholic filtrate. Get as much liquid as you can

out of the solids using a vacuum. Then prepare a further 100 ml of ethanol and

place it in the container we used before. Add the filtered pepper powder out of

again to get a slurry. We repeated the microwave extraction process again on

this in order to get as much of the piperine out as possible.

Allow the boiling mixture to cool down a bit and then filter this as before

collecting the yellow alcoholic filtrate. We then wash the solids with another 50

ml of ethanol. We ended up with about

250 ml of brown filtrate from the two extractions. We now need to distill

off the ethanol so place this into a 500 ml flask and set up for simple

distillation. We can also use some of the ethanol we

recover later on. Distillation is pretty fast. Ethanol has

an interesting property of not looking like it's boiling much when actually a lot of vapor is coming out of it.

After an hour we've distilled most of the liquid. Only about 15 to 20 ml of

liquid remain in the flask. So stop heating and allow to cool. Here's the

ethanol recovered. We have recycled ethanol from this extraction successfully

more than five times in a row. Just topping up each time with a little more

as needed. This ethanol is also very useful for cleaning glass.

whereas piperine is extremely hydrophobic and difficult to wash off

using water. So use 40 ml of the recovered ethanol and place into a 200

ml beaker. Now weigh out six grams of solid potassium hydroxide and add this

to the ethanol. Stir to dissolve or use a magnetic stir bar. This may take some time.

Here's the result. An ethanolic potassium hydroxide solution. To this

carefully add the 15 or so ml of liquid that remained in the distillation flask.

Use a couple of five ml portions of the recovered ethanol to wash out the flask

and add the washings to the beaker as well. You will see some dark brown solid

in the bottom of the beaker. This is a mixture of fats, peptides, resins etc. from

the pepper and will need to filter this out if we want a good quality product.

We used a grade 4 sinter for this but you could try filter paper or even

allowing the mixture to settle and decanting. Filter the mixture and be sure

to wash the beaker and the solids in the filter with a couple of small portions

of ethanol as before.

Pour in order to transfer all the alcohol soluble paper in over. You can see the black

terry solid left in the filter. It's pretty unpleasant stuff and one advantage of using

white pepper is that this is minimal, even to the point that you can skip this filter

stage altogether. Here's the dark brown filtrate. Transfer this back into a 200 ml beaker and

wash the filter flask.

Check out with a couple of small portions of ethanol you should now have

around 75 ml of liquid all together. Prepare a beaker of water and a dropper.

Now slowly drop wise add the water to the alcoholic piperine solution in the

large beaker. You'll see a white or yellow fine precipitate forming. This

precipitate will sink to the bottom of the beaker.

And you'll see a mass of crystals starting to appear at the bottom. Keep slowly adding

the water as long as you see a white cloudy product being produced on addition. At this

point we're done. Chill the mixture down and leave for a good 24 hours to crystallize properly.

Here we are 24 hours later. You can see lots of yellow solid in the beaker. You can see

the liquid in the beaker. Filter off the yellow solid. Note that this may take a little while as the precipitate is still quite fine.

Some procedures tell you to wash with full

Isotone, but we've found this dissolves the product quite well and leads to a considerable loss, so we just leave it on the pump to dry as long we can.

This is the final result.

Here's our still wet crude product from the filter. We put this into a desiccator over anhydrous calcium chloride for a week to dry it out thoroughly.

And here's the result. 3.6 grams of crude piperine. We obviously lost some product in the process, but this means that the original pepper contains at least 3.6% piperine.

You could recul

crystallize this, but if you want to hydrolyze and go to piperic acid, you can perform that

reaction directly on this product quite successfully.

Don't forget that an interesting side product of the hydrolysis is biperidine, which you

can extract from the alcoholic distillate by gassing with hydrogen chloride and then

evaporating the resulting solution.

Here's a couple of grams of biperidine hydrochloride whey, prepared in exactly this way, starting

from pepper.

It is possible.