For one reason or another, we once tested washing some botanically derived terpenes with water as a step in an unrelated process.
Mixing with a fair amount of water, heavily agitating for a bit, allowing phase separation to occur, than capturing and carefully drying the terpene layer.
Changes to smell of solution had been immediate and pronounced, in an interesting way. Overall the intensity/stregnth of the odor was significantly diminished,
some of the heaviest notes seemed to be lost altogether, and other subtle components of the fragrence that did not seem to express well before were now more apparent.
Essentially they got lighter overall, and the more subtle notes that were being overpowered surfaced.
It seemed to pull away a bit of that chemically smell that terps sometimes get as well. Initially, this didn’t make much sense to us.
Yes, terpenes in the presence of water + heat (steam) and/or other substances seem to undergo some mild decomposition reactions and alterations.
However, the initial test was performed without the presence of any heat. In addition to this, we assumed most of the oils present would only be sparingly soluble if that.
We were fairly certain it was unrelated to a change in concentrations of major components (say the aqueous phase was pulling slightly more of x then y).
That lead to the idea that perhaps a minor impurity of a terpene isolate, or an oxidation product of the mixture was responsible.
Very small amounts of impuritys or oxidants can have a staggering effect on the overall smell, taste, and sensitivity index of a complex mixture or single compound.
What they were, and how they were migrating to aqueous phase was eluding us (specifically in the case of what we had suspected to be things like hyperperoxides, plain terpene isomners from degradation, ect).
We figured things like acids, solids, epoxides maybe, ect could feasibly be migrating to the aqueous phase. Anyways, we decided to make testers from the recaptured terp fraction.
Taste wise, the results very similar to almost identical effects overall to what it imparted on the smell. The overall intensity was reduced, the heavier notes seemed to be hollowed out, and the subtleties surfaced.
The interesting part was a noticeable lack of irritation or heaviness that is normally associated with BDTs.
They were certainly much less “harsh” at equal concentrations than the source terps, or any of our BDT preparations in general for that matter.
The initial test was repeated on a variety of terpene feadstock with varying concentrations of various terps, as well as single compound terpene isolates.
We generally saw the same trends (lack of irritation, reduced intensity, lighter notes becoming more prominent/pungent).
Some worked better than others, flavors got muddy in some cases, or even entirely changed taste/smell rather than mellowing out in very rare cases.
Now, we are fairly certain this is at least in part a result of things like acids (and perhaps ph change), solids, ect migrating to the aqueous phase.
However, i recently stumbled upon some literature “Stability of Essential Oils: A Review - Claudia Turek and Florian C. Stintzing” that suggests
hyperperoxides or oxidation products (additional hydrocarbons) could become more soluble in water once degraded, and perhaps partially move into the aqueous phase as well.
“A new approach combining conductivity and pH assessments has been applied to monitor storageinduced oxidation processes in essential oils complementing POV.
For that purpose, stored oils were extracted with water followed by
analysis of the aqueous phases (Turek and Stintzing 2011b). While
mere terpenic hydrocarbons are not soluble in water, oxygenated
derivatives were shown to partly pass into the water phase upon distillation, most likely owed to the capacity to form hydrogen bonds
(Rajeswara Rao and others 2002; Edris 2009). Moreover, Borglin
and others (1950) as well as Mercier and others (2009) reported
that terpenes became water-soluble upon oxidation. Chapard and
others (1972) observed the same effect in oxidized essential oils.
Less stable hydroperoxides and epoxides, formed as intermediates, were suggested to be hydrolyzed into terpenic polyols in the
presence of water (Borglin and others 1950; Lorand and Reese
1950). As a consequence, polar, conductive, and/or acidic secondary products accumulated during terpenoid degradation and
subsequently passing into the water phase, might be captured by
combined conductivity and pH measurements.”
This got me thinking that perhaps, in addition to things like acids, solids, maybe epoxides, ect we could potentially have hyperperoxides and terpene degradation products in the aqueous phase.
Certain hyperperoxides leaching into the water could also feasibly explain the marked difference in irritation, and in some cases smell/taste.
Hyperperoxides and oxidation products can in many cases work as signifigantly greater sensitizers or irritants than the parent compound they spawned from.
They can also exhibit significantly different taste/smell from the parent compound, potentially at significantly greater intensity.
With this in mind, we are experimenting with washing our entire index of strain mixes in this way, and are seeing very positive results in most cases (~90+% of source terp samples seem to go well).
In regards to things like hyperperoxides and oxidation products, all terpenes on our end are stored under ideal conditions after they are received from the manufacturer.
The feadstock terps we are using aren’t old, nor do they seemingly have much general oxidation overall.
We have tried using different vendors terpene isolate stock as well, and well there is some difference in what happens via a wash vendor to vendor even with the “same” source isolate, the trend continues.
We are working on securing analytics capable of testing the aqueous phase as well as the end product terpenes vs the source bottle, but we aren’t there yet.
So, i will propose the question, what do you suspect is going on here? What compounds or types of compounds, exactly, are migrating into the aqueous phase?
The marked lack of noticeable irritation or harshness has us utterly intrigued because generally, that’s one of the main complaints in relation to botanicals.