• If you have a question about commercial production or the hot sauce business, please post in The Food Biz.

heat Extracts: Advanced Home Techniques

ENTIRE POST CURRENTLY IN ROUGH DRAFT STATUS AND INCOMPLETE - CHECK BACK SOON FOR DETAILS ON HOW TO PREPARE ALL SOLUTIONS ETC
LAST UPDATE 2013/10/30 12:52
 
Hello All,
 
So as promised, here is the follow up to the “MacGyver Guide to Extracts” post. In the previous post, I covered a few methods that you could perform using things that you could probably find laying around the house, or purchase at the grocery store. This post will cover more advanced methods that will likely require purchases and more precise procedures. However, it will not require sophisticated laboratory equipment and can still be done at home. Accordingly, this an intermediate guide, and not yet the “Walter White Guide to Extracts” which I will post if and when I get around to performing and photo-documenting the full, laborious and time consuming process. Without laboratory equipment such as vacuum pumps, there will be more degradation of the capsaicinoid compounds, but if done properly, you should still be able to take down a grizzly bear with the final product.
 
This post’s target audience is the scientifically-curious general public, not trained chemists. It will involve some more sophisticated concepts than the MacGyver guide, but is not intended to be a text book and may contain some things that are not 100% accurate so as to avoid confusion - so again, no flames please. QUESTIONS ARE WELCOMED AND ENCOURAGED, as are suggestions if you find something “too simplified” or too far from absolute. MY GOAL WITH THESE POSTS IS TO SPREAD THE KNOWLEDGE AND ‘TRANSLATE’ FROM SCIENTIFIC MUMBO-JUMBO TO ENGLISH – PLEASE HELP ME TO DO THIS WITH QUESTIONS IF YOU HAVE THEM!!!
 
 
 
Section 1 - Introduction
 
Extraction basically boils down to one thing: dissolution. That is, dissolving the desired components of the pepper in an appropriate solvent. Refinement of extracts is essentially 'extracting from extracts' which involves separation of some of the dissolved components from others, and the basic principle is equally simple: solubility. The steps of the process described in what is to follow will each remove more non-capsaicinoid components from the extract. If one follows the entire process (both parts, the second of which is not yet posted), he or she will end up with mostly pure capsaicin. However, there are various points at which one may stop and still have an excellent product.
 
First off, forget about things that you may have heard such as soxhlet extraction – this is absolutely not necessary and actually introduces more impurities and may easily degrade the capsaicinoids. Also forget about using solvents like hexane that are mentioned frequently. Most are undesirable for extraction due to low capsaicinoid solubility (ref: http://lxsrv7.oru.edu/~alang/onsc/solubility/allsolvents.php?solute=capsaicin) and many chlorinated hydrocarbon solvents (e.g. chloroform) are teratogenic and/or mutagenic. They have their purposes for other processes but NOT oleoresin extraction. Many people pretend to know what they are talking about when it comes to these chemicals/processes/etc but you should be skeptical about most of this. Frankly, much of the discussion on the web is categorically incorrect.
 
Why should you believe me and ignore so many others? Well, in my opinion, you shouldn’t; you should always be skeptical and do your own research to confirm any claims made by anyone. I do not consider myself an expert in this particular field; unless you have done extensive research in the field and/or have your name listed first on related peer-reviewed journal publication(s), you are probably not an expert. That said, I am not merely a ‘hobby scientist’ – science is my career – and hopefully without sounding like too much of a c*ck, I do have ample qualifications.
 
1.1 History
 
Capsaicin was first extracted and isolated in pure form over 100 years ago and generally the work of Nelson (1910) is regarded as the first process to obtain a pure product. Since then, there have been many modifications and other techniques developed, but the vast majority still incorporate parts of Nelson’s procedure. I am not taking credit for discovering anything new here; my contribution is merely describing various parts of others’ work in ways that can be done at home.
 
1.2 Types of Extracts: Not just capsaicin
 
The term “extract” can mean a number of things and there are numerous products that are referred to as “extracts” with widely varying capsaicinoid content. Technically speaking, the cellulose from a pepper could be considered an extract. This post will, of course, focus on extracting the good (i.e. hot) stuff.
 
Oleoresin is the most commonly found and discussed hot pepper extract. Even this term is not specific in definition and a particular pepper’s oleoresins can be purified many times and still be considered oleoresin. In other words, oleoresins (even from the same pepper) are not all created equal and, like extracts, they can also vary quite a bit in capsaicinoid content. Oleoresin can be obtained very easily and these techniques are described all over the web (e.g. ethanol extraction). These extracts are often mistakenly referred to as capsaicin extracts, but are far from pure capsaicin. Here, we will discuss how to extract the most capsaicin possible with the oleoresin, and how to refine the extract products (i.e. remove the non-capsaicinoid contents). To give you an idea of what you’ll end up with if you go all the way to capsaicin crystallization, using ripened jalapenos you can expect a yield of less than 1% of the initial DRY pepper weight. Hotter peppers will give you more, but don’t expect a huge amount of the stuff.
 
1.3 Recommended Background
 
SECTION IN PROGRESS – MORE TO COME
Some basic chemistry background is recommended in order to increase quality of results, but not absolutely necessary. It is recommended that anyone who attempts the processes to follow be familiar with the following concepts:
  1. Molecular weight
  2. Molarity (concentration)
  3. Normality (acid/base concentrations)
  4. pH/pOH (acid/base strengths)
  5. Solubility
  6. Hydrolysis reactions including saponification (optional)
  7. Basic alkaloid properties (optional)
 
Section 2 - Materials
 
2.1 A word on safety (IMPORTANT)
 
If handled properly, there is little danger. Some of these chemicals are POTENTIALLY extremely hazardous, however, and if handled improperly one runs the risk of chemical burns, respiratory damage, heavy-metal poisoning, and even explosions to name a few. I'm not trying to be a fear monger; this isn't anthrax we're dealing with, and a bit of knowledge will keep you safe. Better safe than sorry... So, I implore you to familiarize yourselves with the following documents: 
 
http://www.sciencela...?msdsId=9927164
http://www.sciencela...?msdsId=9924999
https://www.sciencel...?msdsId=9924285
http://www.sciencela...?msdsId=9927062
 
It is highly recommended that you download these documents for reference in case of accidental exposure.
 
As I’m sure you’re all aware, capsaicin itself can be quite nasty so wash your hands (especially before using the bathroom – learned this one the hard way lol).
 
2.2 Reagents
Remember, you can stop at various points, so you don't necessarily need all the reagents listed. The further you go, the more concentrated the capsaicin will be in your product. The reagents you will need, in the order in which you will need them, are as follows:
  1. Peppers!
  2. Distilled water
  3. Acetone -OR- Ethanol with dehydration procedure (see prep instructions)
  4. Magnesium sulfate (MgSO4) – or – Epsom salt (will require dehydration procedure)
  5. Sodium hydroxide (NaOH), or potassium hydroxide (KOH) – solid form preferable
  6. Hydrochloric acid (HCl)
  7. Diethyl ether, anhydrous (abbreviated ROR herein)
  8. Barium chloride (BaCl2) (Part II)
  9. Silver nitrate (AgNO3) (Part II)
2.3 Equipment
  1. Glass vials with non-plastic (or protected plastic) caps – scintillation vials are great
  2. Glass pipettes or droppers
  3. Scale accurate to .05 g – make sure this is accuracy not resolution
  4. Volumetric glassware
  5. Glass and/or plastic containers for solutions you’ll be making
  6. Goggles (no exceptions)
  7. Respirator (recommended)
  8. Fire extinguisher
  9. All applicable safety equipment and antidotes are recommended
  10. Gloves, latex or nitrile are best
2.4 Preparation
 
The following will need to be prepared to complete the coming procedures:
 
1. Anhydrous magnesium sulfate
Preparation of Anhydrous Magnesium Sulfate from Epsom Salts:
If you don't want to waste money buying already anhydrous MgSO4, you can make your own with a couple bucks worth of Epsom salt and an oven. Note that some of this will end up in your extract if you stop before ether steps (it is slightly soluble in ethanol), but as long as you don’t way-overdo it with the ethanol-to-pepper ratio it shouldn't be noticeable. You can Google “magnesium sulfate dehydration” and find plenty of info on this process. Comment or PM if you would like further info on this.
 
2. Anhydrous acetone
The acetone you buy is probably already low in water content, but it can't hurt to do this anyways. Add anhydrous magnesium sulfate (MgSO4) to the acetone at roughly 10% by volume (MgSO4 powder should take up 10% the total volume, acetone 90%). Give it a shake and set it aside for at least 30 minutes. Shake it a couple times during the 30 min if possible.
 
3. Anhydrous ethanol
The ethanol you have probably has at least 5% water content. This is because at 95% concentration, ethanol forms what is called an azeotrope with water which essentially means they evaporate together and distillation can't concentrate it any further. So, you should add a bit more MgSO4 - 20% by volume should be more than enough. You can't really over-do it here; nothing will happen other than making more of a sludgy mess at the bottom of the container. Shake it up and wait as described in the previous step. It's OK to have some MgSO4 dissolved in the ethanol.
 
4. 0.25 N HCl
37% hydrochloric acid (HCl) is as concentrated as it gets and is roughly 12 M. Dilute accordingly for a final concentration of 0.25 N.
 
5. 0.25 N NaOH or KOH
Both NaOH and KOH have a single OH so normality is again equal to molarity. The molecular weight of NaOH is roughly 40 g/mole. So, if you dissolve 40 g in one liter of water you will have 1 M or 1 N concentration NaOH solution. So for NaOH, dissolve 10 g per liter to make .25 N. Multiply the mass you dissolve by 1/purity - so if it is 90% pure, dissolve 10*(1/.9) g per liter. KOH is roughly 56 g/mole and exactly the same arithmetic applies.
 
6. 0.025 N NaOH or KOH
Dilute some of the solution you made in step 5 by 10X - 1 part step 5 solution to 9 parts distilled water.
 
Section 3 - Procedure
 
PART 1
 
ALL EXAMPLE IMAGES ARE OF A VERY SMALL SAMPLE AND ARE FOR ILLUSTRATION PURPOSES - YOU CAN DO MUCH MORE
 
Step 1: Prep the peppers
Choose a pepper variety (or mix) to use. The hotter they are, the hotter your extracts and larger your final yield will be (percentage wise). However, it may be more economically viable to use a larger amount of cheaper and milder peppers – you’ll have to decide.
First, dice the peppers up or blend them or whatever you want to get a fine pulp or small pieces (this is where you’ll want a respirator if you use hot peppers). The more surface area, the faster and better the first step of extraction will work.
Next, dry the pepper using just air if possible (oven will degrade product). You can place them in front of a fan for a couple days. Adding a bit off salt on top of the peppers or magnesium sulfate will speed the process but is not necessary. Make sure the pepper fragments are completely dry before proceeding.
 
Step 2: Extract oleoresin
Completely submerge the dried pepper pieces in anhydrous acetone and cap the container. Ideally, you should use 5-10 times the volume required to cover the peppers. The optimal conditions for extraction in acetone have been reported as 1 hr at 40C (lost the reference, sorry, and don’t know which kind of peppers), but several hours at room temperature will work just fine and will not require additional equipment. Shake the container occasionally. After ~3 hours (more is ok), dump the mixture into a beaker, cover with aluminum foil (or parafilm if you’ve got it) and let all particulate matter settle then transfer ONLY THE ACETONE LAYER to a new container. Note that many filters are not compatible with acetone. Using a glass pipette, or better yet a phase separation funnel (essentially a fancy glass beer bong), are probably the best ways but very slowly and carefully pouring the acetone into another container will work satisfactorily. In any case, try to get as little particulate matter as possible. If you have a way to filter the acetone (make sure it is chemically compatible), this is advantageous. Note that additional color does not necessarily mean more capsaicin, and it has been found that the capsaicinoids dissolve much more rapidly than some of the chlorophylls etc. so leaving it to sit for extended periods may be disadvantageous.
Note that acetone liquid and vapors are highly-flammable and inhalation of the vapor poses health hazards. Note also that many plastics will be dissolved by acetone (my wife once made the mistake of putting nail polish remover into a plastic party cup and a short time later found it dissolving the finish on the wood table).
 
The image below depicts the starting amount for this example, but you should follow the text instructions as the images do not depict them accurately.
vjBwWZ7.jpg

Two different types of peppers were used here (obviously). Although this is inside, I do not recommend it. A simple fan blowing over the vessels will be quite sufficient
 
Step 3: Concentrate the extracted oleoresin
In a very well-ventilated area (preferably outside), air-dry the acetone until the consistency is thick. This should be at least a 10X reduction in volume. Before the solution is too thick, transfer it to a container with a chemically compatible cap.
Again, note that acetone liquid and vapors are highly-flammable and inhalation of the vapor poses health hazards.
The image below shows the concentrated extract liquid. In this example, more liquid was added during evaporation so the total volume was reduced more than it appears. Still, I got impatient and you should wait longer until it is more concentrated (I'll do it again eventually and update).
Bpg8AcY.jpg

 
 
Step 4: Dilute and alkalize oleoresin
Dilute the concentrated acetone-oleoresin solution by 5X using the .025 N NaOH/KOH. In other words, add the .025 N hydroxide at 4 times the volume of acetone-oleoresin to get a final volume that is 5 times the original. Give it a good mix every few minutes for the first 10-20 min then put it aside at room temp for 18-24 hours.
 
The images below show the diluted alkalized solutions. Ideally, the dilution should be 5X which may not be apparent from the image.
W7Twmib.jpg

 
 
Step 5: Acidify and ROR-extract
Add .25 N HCl at 9% the volume of .025 N NaOH/KOH and give the solution a good shake. Using a glass pipette or dropper, add ROR at roughly 20% the total volume. Cap (with chemically compatible material) and shake this up every few minutes for 3-4X, then set it upright and wait for the phases to separate. After full separation, using glass pipette or dropper, transfer the ether phase to a new glass vial and cap it. Add more diethyl ether and repeat 2-3X, combining the ROR phase from each extraction in a single vial.
 
Here is the process depicted pictorially.
 
iFmAJu9.jpg

 
First, add the ether and cap the container. Remember to use glass transfer instruments, STAY AWAY FROM HEAT/FLAMES, and to cap your ether stock and protect it from light for best results.
In the above image, notice the separate layers (it has not been shaken yet). On top is the ether phase while the aqueous phase is below.
 
Shake the mixture and wait for the phases to separate as shown below. (Forgive the background peppers, I got bored waiting)
 
CevH54a.jpg

 
Notice the additional color that has been imparted to the ether - compare the above 2 images.
 
In the image below, the red peppers have undergone the second ether extraction (orange described in next step). Notice the decreasing color of both the aqueous and ether layers from the above image to the below and the next. Observe left ignore right for now.
 
mcW0y7F.jpg

 
Observe left, ignore right for now.
 
Or3BhMJ.jpg

 
Observe left, ignore right for now.
 
Step 6: Distill ROR phase
NO HEAT!!! NO OPEN FLAMES! NOT EVEN A NEARBY TOASTER OR HOT SURFACE!!! THIS STUFF IS CRAZY FLAMMABLE AND DOES NOT REQUIRE FLAMES TO IGNITE. PLEASE DO NOT BE THE FIRST RECORDED PEPPER-RELATED DEATH!!
 
Evaporate the ether phase using a fan and outside or in an extremely well-ventilated area. You will see the oleoresin start to precipitate, as shown below, as the saturated ether is evaporated. This is likely hotter than any commercial oleoresin you have encountered for whatever type of pepper you chose.
 
ATLkIGz.jpg

 
Continue the evaporation until you have a consistent thicker substance.
 
--------------------------
At this point, the product is still considered oleoresin, but if everything has been done properly and you used sufficiently hot peppers, it is unlikely that you will have encountered a hotter oleoresin before. See the image below; THIS is ‘true’ oleoresin i.e. without the adulterants that are present in so many others. After the ROR has been removed, it is safe to consume (you can do an ethanol ‘wash’ if you want to be sure but this will degrade the product slightly. Just dissolve in ethanol and evaporate). Take a toothpick and get a tiny amount then spread (touching wont transfer much at all due to hydrophobicity) it on your tongue.
---------------------
 
PART 2... to come
 
NEXT STEPS TO FOLLOW: Next, similar processes will be used to precipitate more and more components of the oleoresin as it nears pure capsaicin. These steps will require additional materials/equipment, so it will be in part 2 of the post since what can be obtained by the above procedure may be satisfactory for many people. The last step will require a reflux apparatus which can be constructed relatively easily, but it is still more investment. This stuff will be coming if people want it, so please let me know your thoughts on what has been described thus far and what you would like to see next.
 
Spread the knowledge! Debilitating heat for all!!
 
Glad there is some more interest. Thanks for expressing it.
Balac said:
OK great---I will buy some BrCl now. I am in the boon docks and there is nothing near me but a walmart so Ebay is called for once again.
 
Crystals are what I want so this is a good update to the process. Still have not received all of the chemicals and glassware I need to reproduce your process here. As soon as I do I will publish how I did here.
thanks for your work
Balac, as you probably know, BaCl2 is toxic so be careful and download the MSDS. Also, you should consider synthesizing it. With $3 of BaCO3 purchased from a pottery supply store anf a bit of pool acid I made about $50 worth of BaCl2.
Also,dont put all your eggs in one basket here when it comes to the processes - try small batches until you get each step just right. I'm still tweaking based on a paper from 1977 that is not very high quality and another from 1910 that is almost a different language now haha and there will be some changes.
You will need some silver nitrate solution which can be expensive. Don't buy it just yet though, I can send you some.
Until I update again don't put too much faith in the last step working the first time.
 
impending_bending said:
You will need some silver nitrate solution which can be expensive.
 
Dont get it on your hands...it will not wash off.  In fact you wont even know you have it on your hands until a few days later after UV light has darkened it.  Your hands will be black and like I said, it doesnt wash off....you will have to wait to grow new skin.  Can also become explosive when mixed with the wrong things-->siver fulminate.
 
cool write up, was this information detailed in that book i sent you? i remember pming someone about the acetone method, i think that was you?
if it was in that book could you let me know where in the book it was?  page numbers etc.
 
didn't read the whole deal yet, but right off the bat im curious as to why the soxhlet is poo pooed so early. i cant think of any easier way to carry out any extraction.
 
couple of questions.
 
soxhlets can be had for relatively little, and they allow you to use exceptionally little solvent. if you are lucky you can even get an allihin with a sidearm take off that allows you to recover solvent from one apparatus.
while not cheap, they seem to me atleast to vastly simplify the extraction. one could even use acetone in a similar, more efficient manor. why not consider the soxhlet at all?
 
n-hexane is indeed a poor solvent for this, however it is insanely cheap and on hand readily.
that reference is .001 Moles / liter? that would be .3 grams of cap  correct?  how much cap is in a typical pepper? i would think in the milligrams.
 
what impurities can soxhlets introduce?
 
why bother with the ether? is there no suitable substitute? seems like any number of polar aprotic solvents would do. DCM or dmso?  seems like the dangers of ether far outweigh the potential and imo abstracted health effects of chlorinated solvents.
 
have you thought of any simple solvent recovery methods? especially the ether...if bought it will be spendy. 
perhaps a simple warm water bath with a moonshiners type submerged worm coil condensor?  one could use a lightly stoppered flask with SS brake line tubing i would think.
 
however... the problems with storing ether, while i think are somewhat overblown, cant be ignored. 
ive always hated evaporating valuable solvents to the atmosphere. in ochem we would just boil off chcl3 WITHOUT fume hoods.... with nothing but open doors and windows.
 
 
 
 
ha wow. queequeg - some good questions in there, thank you. I'll be happy to answer them - a bit later though since it will take some time. And no, it didn't come from any book. The process is modified from ones presented in several publications to be more suitable to perform at home without tons of equipment.
It seems there has been more interest in extracts lately and luckily I have had more free time as well. I'll try to answer these questions and finish the guide as soon as possible. At the least, I'll get to some of those questions tonight
 

Sawyer

Extreme Member
Tim, I may not be the only one, but you sent me a pdf.  Sadly, I haven't yet had time to investigate it further.  Still on the to do list.
 
Sawyer said:
Tim, I may not be the only one, but you sent me a pdf.  Sadly, I haven't yet had time to investigate it further.  Still on the to do list.
s-ok, its a big boring book, i couldn't be bothered myself. but yea i sent it out to tons of folks asking them to relay any of the good bits, and i dont think anyone has gotten back to me yet with any pertinent information.
 
impending_bending said:
ha wow. queequeg - some good questions in there, thank you. I'll be happy to answer them - a bit later though since it will take some time. And no, it didn't come from any book. The process is modified from ones presented in several publications to be more suitable to perform at home without tons of equipment.
It seems there has been more interest in extracts lately and luckily I have had more free time as well. I'll try to answer these questions and finish the guide as soon as possible. At the least, I'll get to some of those questions tonight
 
no hurry please, i didnt know about this thread untill you linked it yesterday.
 
lol, im trying to not be defensive about the soxhlet, full disclosure tho i love the soxhlet apparatus. its a lovely ellegant piece of glassware imo, and yea i did do that hexane extraction thread(albeit with MUCH MUCH less research than you evidentally did), so i guess im kinda bummed its dismissed so quickly. especially since you can get one for like 40 bucks easy. whenever i find myself on a tangent about cool lab glassware, i always find myself using the soxhlet as an example.
 
 
i understand this is supposed to be doable with cheap easy to get stuff.
 
to me it just kinda feels like one of those...kitchen remodel books saying all you need is a hammer and cordless drill PERIOD.
sure you can get by without better equipment( miter saw, router table, table saw), but its important to recognize that these pieces of equipment while spendy have their place.
 
i think what you are onto something truely awsome and usefull here.
 
from what ive gathered via pm's etc ALOT of folks are interested in making extract as a way to kind of... get rid excess pods. removing the oleoresin and discarding the pods themselves is lucrative to MANY folks who grow tons of plants or those who make sauces
 
to that end, i think if this method could be scaled to some extent such that its useful to some folks, it would be greatly appreciated... EVEN if that means using a less efficient method( substituting ether with something safer/cheaper), and by using real equipment suited for the task... big ole sep funnels, filteration setups, solvent recycling setups etc.
IMO if the above could be accomplished with like... 300 bucks worth of chemicals and equipment many folks would jump on that. agreed 300 bucks will not buy you many pieces of glassware.
 
to me it it almost seems like you have taken a lab excercise and repeated it without glassware, and thats great, however while interesting, i dont think its particularly usefull to the above mentioned folks.
 

Sawyer

Extreme Member
One potential problem I see with soxhlet extraction, or any technique involving elevated temperatures, is that capsaicin is relatively thermally unstable and will begin to decompose when heated.  I don't know the specifics of decomposition rate vs. temperature, but it does happen.  One method of capsaicin extraction that avoids this problem is supercritical CO2 extraction, but that process is way beyond "kitchen chemistry" levels.
 
Having said that, Tim, do you have a link for a soxhlet apparatus for $40?
 
there are tons out there on ebay.
http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313&_nkw=soxhlet&_sacat=0&_from=R40
 
just have to find one.
 
i dont honestly understand why there are so many out there? to my knowlage they are used only in a few areas, food science, soil analysis etc. yet there are HUNDREDS on ebay all the time. i dont get that.
 
is capsacin really unstable? the stuff is cooked with all the time surly thermolysis does not occur at a significant rate at the 62C that hexane boils at. acetone im assuming is not far off hexane... diethyl ether boils absurdly low, but is absolutly not suitable.
 
heat however, obviously increases the efficiency of the extraction, and is an obivious motive force to pump solvents without need of pumps etc.
 
Sawyer said:
One potential problem I see with soxhlet extraction, or any technique involving elevated temperatures, is that capsaicin is relatively thermally unstable and will begin to decompose when heated.  I don't know the specifics of decomposition rate vs. temperature, but it does happen.  One method of capsaicin extraction that avoids this problem is supercritical CO2 extraction, but that process is way beyond "kitchen chemistry" levels.
 
Having said that, Tim, do you have a link for a soxhlet apparatus for $40?
This is a major point in the answers to a lot of your questions qq, answers to follow
queequeg152 said:
cool write up, was this information detailed in that book i sent you? i remember pming someone about the acetone method, i think that was you?
if it was in that book could you let me know where in the book it was?  page numbers etc.
 
didn't read the whole deal yet, but right off the bat im curious as to why the soxhlet is poo pooed so early. i cant think of any easier way to carry out any extraction.
 
couple of questions.
 
soxhlets can be had for relatively little, and they allow you to use exceptionally little solvent. if you are lucky you can even get an allihin with a sidearm take off that allows you to recover solvent from one apparatus.
while not cheap, they seem to me atleast to vastly simplify the extraction. one could even use acetone in a similar, more efficient manor. why not consider the soxhlet at all?
 
n-hexane is indeed a poor solvent for this, however it is insanely cheap and on hand readily.
that reference is .001 Moles / liter? that would be .3 grams of cap  correct?  how much cap is in a typical pepper? i would think in the milligrams.
 
what impurities can soxhlets introduce?
 
why bother with the ether? is there no suitable substitute? seems like any number of polar aprotic solvents would do. DCM or dmso?  seems like the dangers of ether far outweigh the potential and imo abstracted health effects of chlorinated solvents.
 
have you thought of any simple solvent recovery methods? especially the ether...if bought it will be spendy. 
perhaps a simple warm water bath with a moonshiners type submerged worm coil condensor?  one could use a lightly stoppered flask with SS brake line tubing i would think.
 
however... the problems with storing ether, while i think are somewhat overblown, cant be ignored. 
ive always hated evaporating valuable solvents to the atmosphere. in ochem we would just boil off chcl3 WITHOUT fume hoods.... with nothing but open doors and windows.
 
 
 
Answers in line, or will be momentarily if not yet
 
No in linen on phone. Going to have to be short and sweet here. 
 
Thank you for the kind words. 
No it was not from any book, it is from publications spanning 100 years. Although, I don't think you may have sent me that book. 
 
Basically, soxhlet is undesirable for exactly where reason safer mentioned. Also, you extract many things besides capsaicin. It's great for oleoresin that is intended to keep flavor etc, but not for isolating cap. 
 
I'd have to look further into hexane to give you the whole list of reasons, but the best reason, or at least most readily apparent, is that acetone has been used before by many research groups with great success. 
 
The term 'impurities' here, for the purposes of this post, refers to non capsaicin compounds. 
 
Ether is an excellent chemical for these purposes. The whole list will have to wait as will full answers to those questions. The main danger is fire, not health. With proper handling it is relatively safe. It can be used for the phase separation, it lends itself extremely well to vacuum distillation, which is the best way to avoid degrading the capsaicin, and many more. Also, it has been used countless times for over 100 years for exactly this process so that alone speaks volumes.  
 
Recovery of solvents would be a fun project. Why don't you get on that ;)
 
Remind me and I'll show you a great storage mechanism for ether. 

Robisburning said:
 , thank you Dr. Bending!
Lol how did you hear this? Or is this just a coincidence? 
 
Robisburning said:
I actually thought you had your PhD, was I wrong,  from context it sounds like it might have just become official?  If so congratulations!
No you were not wrong at all, I just don't know how you knew that lol!?!?! Not just becoming official but thanks anyways 
... Now I remembered how you knew...
 
The half-life of capsaicin is 2.3 to 4.1 minutes. There is nothing that good scientists won't quantify!
 
They killed mice;rats;hamsters; and rabbits by injecting or coating them with Capsaicin. The author of the study, T. Glinsukon, concluded that the acute toxicity of capsaicinoids as a food additive in mankind was neglible. If humans are about as sensitive as mice, the acute fatal toxicity dose for a 150 pound person would be about thirteen grams of pure, crystalline capsaicinoids, which frankly, sounds high to us. I think that less than that would be lethal.
https://www.fiery-foods.com/article-archives/86-capsaicin/1823-the-nature-of-capsaicin
 
OK, so I had to get off my ass and write something up here since you peeps are into this. First of all I am a BS in Chemistry and MS in Physics but I have not done any Chemistry since 1976 when I graduated. It is not a field that has a long half-life in retention so think of me as a dinosaur in this and just a good reviewer of literature. Bending is a lot better than me for sure.
 
First of all Hexane is NASTY stuff and according to http://peopleforethicalliving.com/health-and-fitness/food-choices-nutrition/dangerous-food-additives/
Hexane is actually a byproduct of gasoline manufacturing. It’s also earned itself the dubious reputation of being a neurotoxin and air pollutant. “Noxious” is a good word to sum up the stuff’s properties. But despite hexane’s obvious dangers to human health, the chemical is regularly used by soybean processors as a solvent. Soaking soybeans in hexane separates the beans’ oil from the protein, allowing nutrition bar and other food producers to pump their products full of soy nourishment.
The use of hexane in nutrition bars is bad enough, but what’s worse is that many bars’ producers use misleading labels like “all-natural” and “made with organic ingredients.” Consumers reach for a Clif, Luna, Mojo, Odwalla, Balance, or Zone Perfect Bar thinking that they’re purchasing a healthy, eco-friendly product.
And from http://www.westonaprice.org/know-your-fats/some-additives-in-vegetable-oils we hear that:
The EPA now categorizes hexane as a HAP (hazardous air pollutant), included on the list of 189 toxic chemicals. Inhalation of hexane can damage the nervous system, leading to numbness in the hands and feet, followed by weakness in the feet and lower legs. Paralysis may develop with continued exposure. Most at risk are those working in closed industrial facilities with hexane- containing solvents and glues. At very high levels of hexane in the air, signs of damage to sperm-forming cells in male rats occur.
 
I am sure that queequeg152 knows what he is doing and has the equipment to do the process correctly but it is not a solvent to be used for extraction of capsaicin that might be ingested by humans..
The solvents are always present is small quantities in the resultant chemical.
 
I had good results in following impendings extraction procedures but having trouble with the crystallization. Found a old crystallization (1910) approach on the net at http://books.google.com/books?id=VPfyAAAAMAAJ&pg=PA420&lpg=PA420&dq=capsaicin+crystallization&source=bl&ots=HWWz0n-q1i&sig=BPLtGV7oKRLpEDPOknIC7n9cVl0&hl=en&sa=X&ei=UKbXUvn5MM3DoASJi4DIBA&ved=0CFMQ6AEwBTge#v=onepage&q=capsaicin%20crystallization&f=false
Also found this partial crystallization procedure form the 70s http://link.springer.com/article/10.1007%2FBF03045391#page-1
I will keep you all informed as I learn anything else. The main thing here is that it is tough to crystallize the capsaicin because there are so many of them in the mix.
Thanks
 
impending_bending said:
No it was not from any book, it is from publications spanning 100 years. Although, I don't think you may have sent me that book. 
 
Basically, soxhlet is undesirable for exactly where reason safer mentioned. Also, you extract many things besides capsaicin. It's great for oleoresin that is intended to keep flavor etc, but not for isolating cap. 
 
I'd have to look further into hexane to give you the whole list of reasons, but the best reason, or at least most readily apparent, is that acetone has been used before by many research groups with great success. 
 
The term 'impurities' here, for the purposes of this post, refers to non capsaicin compounds. 
 
Ether is an excellent chemical for these purposes. The whole list will have to wait as will full answers to those questions. The main danger is fire, not health. With proper handling it is relatively safe. It can be used for the phase separation, it lends itself extremely well to vacuum distillation, which is the best way to avoid degrading the capsaicin, and many more. Also, it has been used countless times for over 100 years for exactly this process so that alone speaks volumes.  
 
Recovery of solvents would be a fun project. Why don't you get on that ;)
 
Remind me and I'll show you a great storage mechanism for ether. 

Lol how did you hear this? Or is this just a coincidence? 
 
1.ok i thought i DID send you this book, if not. if you like i could send it your way, just need an email.
 
2. regarding thermolysis of capsacium, has this even been established? secondly, its worth noting that the material being extracted is only being exposed to the BP of the solvent being used rite... so 62c for hexane. are we saying the soxhlet is unacceptable because at 62c capsacium is degraded? i can tell you from experiance... that what i recovered from my hacky extraction technique was indeed uncomfortably hot at rice grain sized dabs.
i even had an "incident" with hot water and a beaker that caused sever irritation of my throat. evidently capsacium is far too volitile for casual treatment. 
 
3.
acetone is even cheaper than hexane fwiw. but i think acetone is used due to its strong polarity. it should pick up all sorts of water soluble stuff including capsicum. ( im assuming capsacin is fairly polar by the looks of the molecule? cant actually find any dipole moment numbers tho).
the ether is simply the non polar solvent you are using against the aqueous. that being so, its entirely probable that it could be substituted quite nicely for a non flamable if not less volatile solvent like dcm or chcl3. yes ether is probably alot better, however from what i recall, almost any solvent can be sucessfully substituted in a L2L extraction, you just might need more solvent, and colder temps, even more extractions even. 
 
i understand what you mean by its the solvent of choice for 100+ years, but remember this is in scientific journals. they are extracting mg quantities under fume hoods using the best most efficient techniques available.
however the best most efficient techs are almost never the most practical. what we really need to do is dig out case studies etc from manufacturing processes, maby even patents. im almost 100% sure ether would not be used on even a semi industrial scale. for obivious reasons.
 
FWIW im not trying to tell people to not use ether! just saying its likely not necessary, and its worth noting that its not the only option. ether is insanely easy to make in your own home provided you have some rudimentary glassware... are not stupid.  likewise chlorinated solvents are easier still to make. 
 
 
4. regarding the recycling of solvents, if you actually look at my thread, i recover like 90% of the hexane i used with a simple libig distil. apparatus. i store old solvents in mason jars to be reused whenever. the hexane evidentally needed to be dried however.
 
 
@ balac.
 
Yes hexane is indeed nasty, remember those poor girls working in china that were exposed tononstop hexane vapors while cleaning screens? i think they had neural damage like you note. but again, its a cheap non polar solvent, infinatly usefull in a number of ways. if you want something safer, look at cyclohexane, tho because it is not a cheap petrollium distillate, its like... 8x more .
 
i think cyclohexane is actually made from benzene somehow.
 
someone in my thread made a good point about hexane having possible traces of benzene present. my msds for my jug says its less than like 0.002% benzene? but yea i would not trust it to be used for soybean oil extraction etc.
 
edit:
 
when i get a chance ( and some cash... just payed tuition) i want to give this a run myself. i feel like im  starting to sounding like a... backseat driver or w.e
.
 

Sawyer

Extreme Member
queequeg152 said:
2. regarding thermolysis of capsacium, has this even been established? secondly, its worth noting that the material being extracted is only being exposed to the BP of the solvent being used rite... so 62c for hexane. are we saying the soxhlet is unacceptable because at 62c capsacium is degraded? i can tell you from experiance... that what i recovered from my hacky extraction technique was indeed uncomfortably hot at rice grain sized dabs.
i even had an "incident" with hot water and a beaker that caused sever irritation of my throat. evidently capsacium is far too volitile for casual treatment.
 
As I said, I don't know the precise details of capsaicin decomposition rate vs. temperature, but it most definitely occurs.  This is one reason why pepper heat often "mellows" when cooked in a meal.  It's a reason at least one method of sample preparation for HPLC quantification involves sonicating samples in ethanol at room temperature.  It's also one reason synthetic analogues are sometimes used in medicinal preparations instead of capsaicin; the analogues are more thermally stable and better able to withstand the preparation process.  A cursory web search didn't turn up anything that directly quantifies the decomposition rate vs. temperature, but did turn up a few papers that assume thermal decomposition and go from there.
 
I'm not saying this means soxhlet extraction is useless, just that some fraction of the capsaicin may be lost.  It could be that the amount lost is negligible, especially for low-boiling point solvents, but it is still a factor to consider.
 
ok well, maby i will dig up this information. that book should at least reference some papers that i may or may not have access to.
 
that will be my contribution to this thread lol.
 
the decomposition data HAS to be available... i mean just for GC work alone, it should be way way available. maby sigma has some papers on their website i an scrounge.
 
ok watch out, i been reading
 
nothing yet with respect to oleoresin specifically, but alot with respect to powders.
there is a problem with this book... the OCR is abominable, its verry difficult to skim for key information in the traditional manner. ill poke around it again some later on.  i DID however see references and diagrams detailing soxhlet-like equipment designed for oleoresin production. the equipment apparently uses hexane and alcohol. it sounded like the hexane extract was treated with the alcohol to remove water solubles in a counter current apparatus then returned to the solvent delivery mecanism for further percolation through the chilies. 
 
 From the PCA it can be
seen that the HD sample showed the highest quality
in terms of capsaicin content and hotness.
On the
other hand, the FD sample showed the highest quality
in terms of colour and ascorbic acid content, whereas
the SD sample showed the least in all qualities. This
may be because the SD sample was very exposed to
the air and also took a long time to dry (Daood et al.,
1996; Mangaraj et al., 2001).
 
 
...it  was  then  dried
using  three  drying  methods:  hot  air  drying  (HD);
freeze drying (FD); and sun drying (SD).
The fresh
Chee fah chilli without drying was used as a control.
SD  was  conducted  by  spreading  blanched-cut
chilli on a net in a single layer and exposed directly to
sunlight (approximately 37oC). The thermometer was
placed on an empty tray besides a net of chilli. This
method was dried for 8 hr per day. A temperature of
60oC was used for the HD
. The blanched-cut chilli
was  placed  on  perforated  tray  which  has  an  area
of  approximately  0.2  m2.  Freeze-drying  chilli  was
performed at -50oC, 5 Pa in a freeze dryer. All the
dried chilli samples were taken when the moisture
content  obtained  was  approximately  10-13%
 
 
this same 2012 paper references prevous work done by others, here is some excerpts
cited in this pdf:
http://www.ifrj.upm.edu.my/19%20(03)%202012/(33)%20IFRJ%2019%20(03)%202012%20Meenune.pdf
 
Topuz and Ozdemir (2004) reported that sun-dried Turkish
paprika chilli, which was processed for 5-7 days, lost
24.6% of the capsaicin content (approximately 12-14% moisture content). Oven-dried Turkish paprika
chilli, which was dehydrated at 70C for 90 min, lost
21.5% of the capsaicin content. On the other hand,
thermally-treating  chilli  at  210C  was  reported  to
increase  the  capsaicin  content  (6.1-924.9%).
  This
was  caused  by  the  dehydration  of  the  food  matrix
and  improved  extractability  of  capsaicin  by  cell
 
 
here is the 2004 topuz et al paper... unavailable to us plebs.
http://www.sciencedirect.com/science/article/pii/S0308814611007242
 
 
here is another paper that is investigating the effect of peroxidaze enzymes on the effect of capsacinods in powedered spices etc.
i dont know the date of this paper. after 2005.
http://www.aseanfood.info/Articles/11017242.pdf
 
this was taken from the abstract
 
Heating and drying resulted in a
21.7% to 28.3% degradation of the initial capsaicinoid content, the three major capsaicinoids showing similar heat susceptibility. During storage at
ambient temperature over 6 months with and without illumination, further degradation of the pungent principles by 6.8 –11.9% was observed.
Since residual enzyme activities were assumed to cause capsaicinoid losses, soluble peroxidase (POD) activity was investigated. It was shown that
immediate thermal treatment of the plant material did not result in a complete POD inactivation even under rigorous temperature – time regimes. In
contrast, a regeneration of about 30% of initial POD activity was found in those samples which were first blanched at 80 °C for 5 and 10 min and
then minced. However, no correlation between POD activity and capsaicinoid losses could be established.
 
 
In contrast, in chili powders obtained from
blanch ed fresh material capsaicinoid concent rations were in the
range of 2 .0 –2.3 mg/ g dry matter (minced be fore heating) and
2.0 –2.6 mg/g dry matter (heat ed prior to mincing) irrespective
of the thermal treatmen ts applied. On an average, the pungent
principle s decreased by 11.9% (minced before heated ) and 6.8%
(heated before minced) in relation to the initial capsaicinoid
contents.
 
 
 
this paper seems to dispute the relationship between peroxidase and storage related degredation of capsacium... however if you see the above, it does seem to suggest that storage past 6 months benefits from "blanching" at 90c prior to mincing and drying. the explaination for this is absent or just not clear to me.
 
 
It is assum ed that
capsaicinoi d decreas e is due to non-enz ymat ic degrada tion at
ambient temperat ure, indepe ndent of ligh t exposur e.
i take this to mean exposure to air and maby microbial activity.
 
from what ive read i gather that:
 
1. heating is not a big deal with respect to powders. heating past 80-90 seems to yield a less than10% loss in capsacinods
2. vacuum packing in addition to freezing is not necessary, refrigerated storage alone seems to greatly hault the degredation of stored powders. 
3. heat treating prior to mincing is almost universally superior to mincing then blanching, with respect to powders and storage. 
5. enzymes may or may not be responsible for longer term degradation, as well as immediate degredation ( matter of days) as suggested by the topuz paper. this is refuted by the german paper. the german paper seems to suggests that desication under oxygen atmosphere was responsible for the higher degredation rates observed for non heated samples. 
6. light has all but 0 effect on storage of powders as well as "capsaicin solutions"
Kopec,DeBel lis and Irwin (2002)
 
 
google book:
http://books.google.com/books?id=uNcFx-8uaswC&pg=PA555&lpg=PA555&dq=Dihydrocapsaicin+decomposition&source=bl&ots=uvxDeB52uL&sig=Sn7j-yA5djjDb7mzW9wUzB-Atrk&hl=en&sa=X&ei=J3jYUuzrHOjKsATPx4CYAQ&ved=0CEQQ6AEwBA#v=onepage&q=Dihydrocapsaicin%20decomposition&f=false
 

salsalady

Business Member
clarifications- since we are getting all technical here~~~
 
Capsicum is a plant type
Capsaicin is one of several capsaicinoids
Capsaicinoids are the chemical compounds that give the sensation of heat in chiles/chillis
 
 

16,000,000

Capsaicin

15,000,000

Dihydrocapsaicin

9,200,000

Nonivamide

9,100,000

Nordihydrocapsaicin

8,600,000

Homocapsaicin, homodihydrocapsaicin

160,000

Shogaol

100,000

Piperine

60,000

Gingerol

16,000

Capsiate
 
http://en.wikipedia.org/wiki/Scoville_scale
 
carry on~
 
Top