Terpene loss due to drying

[Wiener_Demeanor]

Hello dear OG community.

I have found an old study of terpene loss due to the process of drying, specifically loss of total oil, and rate of transformation of monoterpenes to sesquiterpenes. Unfortunately, researches werent introduced to curing of cannabis plant material, which may have prevented loss of terpenes. However, company called Eybna did some research (altough i couldnt find research paper), and states that:

“Findings show that at the fresh, planted state, a cultivar has the highest expression of monoterpenes like Beta Myrcene, Alpha Pinene, Beta Pinene, and Limonene. After one week of drying and curing, each of these terpenes decreased significantly — Beta Myrcene content decreased by 55%. While monoterpenes were decreased during the curing process, sesquiterpenes like Alpha Humulene and Beta-Caryophyllene were increased. Sesquiterpenes almost doubled in their ratio from the total terpene content in data taken after the harvest processes were complete, with Alpha-Humulene increasing 100% and Germacrene increasing 154%. (…) The study results also showed the significant evaporation curve of some other highly volatile compounds responsible for the cannabis top aromatic notes.” - Researchers Reveal How Curing Cannabis Affects Terpene Levels | Ganjapreneur

…which would suggest same happens while in curing also.

This is only study I have found, if you have any newer data, please share so it can be examined.

The Volatile Oil Composition of Fresh and Air-Dried Buds of Cannabis sativa.pdf (372.9 KB)

They saw loss of 31% of volatile oils after 1 week of drying, 44.8% after 1 week of drying and 1 month of storage, and 55.2% loss after 1 week of drying and 3 months of storage, with significant change of monoterpenes to sesquiterpenes, as shown in table below.

Table below shows exact ammount of terpenes for each drying period.

It seems best suited to extract terpenes when fresh cut, and add sesquiterpenes that would be express after curing like b-caryophyllene from lets say Copaiba essential oil or other, then cure plant material with preferable method, altough from my studies and understanding of curing process, i am concerned that the extraction of terpenes may hinder any further production of cannabinoids, even when done at low temps, supported by some carrier gas in vacuum oven then cold trapping it, since loss of terpenes may interfere with biological processes that cause cannabinoid production in curing, and it deviates from all known temp/hum variables of curing process that users say produce best yield/potency.

I would like to see results of THCa and CBDa levels of fresh vs cured cannabis plant material, if anyone has some, please share with me. =)

@Purple-N-Hairy I know you were interested in THC levels of fresh vs cured, so far i found no studies, only some bussines growers stating that extracted fresh material yields less oil. Search for truth goes on!

Peace

[cannabissequoia]

@Wiener_Demeanor

Search for truth goes on!

Indeeeeed…

Without reading the paper my immediate curiosity is what the drying conditions were beyond “brown paper bag, 3 months, room temp” – That’s not how most of us manage the harvest (anymore…right?). Repeating the research with updated practices & equipment would eliminate any issues with brown paper wicking away moisture/VOCs. Because it does do that, (IME).

The extreme environmental differences across the world affect/direct harvest techniques necessarily.

[Purple-N-Hairy]

@Wiener_Demeanor

some bussines growers stating that extracted fresh material yields less oil

Thanks for your efforts, @Wiener_Demeanor - that little snippet of info is reason enough to continue drying my trim material before doing and RSO run.

[Herbie]

Even established practice should be compared with some other curing methods. Including drying with temps below freezing and at refrigerated temps before the cure.

Thanks for posting this.

[ChemicalDependant]

Drying below freezing; now there’s an interesting thought. Live resin is my ideal but I’m not likely CO2 extracting at home.

[Oheeeoh]

I have always stored my (dispensary bought) buds in mason jars that were vacuum sealed using one of these.

The more I learn I’m starting to think that’s not the best way to store my buds.

[Wiener_Demeanor]

@cannabissequoia oh how i wish there was a controlled study that included curing in sealed environment… so far, nothing… altough numbers may be off, it well confirms my and others experience, that new flavours come in after curing, meaning those sesquiterpenes get formed from monos…

@ChemicalDependant yes, there is water cure, lotus cure, low and slow fridge cure… i cannot say which is better, since all info is the user experience, “dude, the best smoke ive had in last 3 years” is an answer for almost each of exotic cure method…

@Oheeeoh should be good method, oxygen free environment prevents terpene oxidation, saves some flavour, but it all depends on what you bought…

@Purple-N-Hairy ive seen regular extractors also say this, but i cannot understand why, there is no literature, no tests, i cannot do it myself, where im from its illegal, no labs, i have to send cross the border, maybe ill bite the bullet… only thing i know is, that while curing, anaerobic bacteria help to dissolve chlorophyll and sugars… it may be that the potency increase many mentioned comes from entourage effect from b-caryophyllene (stoney one) only, and not further development of cannabinoids…

[ChemicalDependant]

I saw a post just yesterday about affordable chromatography kits, I think.

[Purple-N-Hairy]

Chromatography kits? I don’t know how much data you can learn from those things, do you? If using chromatography, I’m much more familiar with the use of instrumentation such as GC or HPLC or GPC, UHPLC or a variety of other analytical instruments. But chromatography is a somewhat general term for the study of separations science.

[Wiener_Demeanor]

i would need to know exact thc test for 1 sample, *so i can compare, but i could also visually see if there is big enough difference… there is an app for android that needs 3 samples of chromatography test with known concentration, to then measure others in precise percentages… ive looked into it allready, and this will be the route to go for me, as i plan to do all kind of weird things to my herbs…

[ChemicalDependant]

Optical cannabinoid UV measurement

So this is probably more for the nerdiest among us, but I found a paper that shows absorbance of different cannabinoids. I was looking it over and I think building an inexpensive detector would be feasible: [image] [image] 275-280nm LEDs are easy to find, but it seems like all the cannabinoids have a similar absorbance, and all of the acid forms do as well. Without a two color measurement, I’m not sure how useful it would be. It seems that the acid forms have at least 10x higher absorbance…

Honestly… I may have confused a few posts or something. I can’t seem to find the post; I remember it tested a very nice spectrum, 12 separate cannabinoids/terpenes.
Sorry, I certainly do not know enough about chromatography to be of any help; I just meant it direct you to the topic I read. Which may or may not exist…

[Heritagefarms]

Wonder what those eleven unknowns are …

[Wiener_Demeanor]

mmmm juicy… worth looking into… *what they stated: “In conclusion, TLC is very useful to rapidly screen many samples for the presence of cannabinoids in crude plant extracts, or in eluting fractions collected after preparative chromatography. However, reproducibility of TLC depends on several parameters, e.g., relative humidity. Compared to other separation methods, TLC performances are also very low. Consequently, unequivocal identification of cannabinoids spots requires further methods.” Also, they used chloroform as a solvent, which is impossible to get where im from, and dangerous to make on my own… Im more interested in spectrophotometry… I didnt came upon this method in any research paper i looked into it, now im on fire… It should be DIY-able with some think-tankering… :3

[Wiener_Demeanor]

tnx for pointing out that thread mate! i think we can find a way for this to work! <3