What's new

Kava Science So...what evidence do we have that heat destroys kavalactones?

yepimonfire

Kava Enthusiast
I keep hearing it does but haven't found any source specifically showing it does.
I found this quote on the old forum:

Owner of Hawaiiankava.com
"About three years ago, a test (using HPLC) was done on boiling the kava beverage (~212F). Loss after a few minutes at that temperature was considered insignificant. Less than 5% of the kavalactones were lost."
[The link is broken, but the quote was from the owner of Hawaiiankava.com]

More Evidence
"This one's more about special lab equipment based extraction so I can't be sure it applies here, but the graph on page 190 (and following pages) shows that, in general, the percentage of extraction increases as temperature increases. Yangonin extraction is essentially 0% until you reach boiling point"
[link seems broken to me, but you could try it: http://144.206.159.178/ft/553/42507/769267.pdf]

Kava: The Pacific Elixir- Lebot et al. 1997
"Various authors have suggested that the two compounds isolated by Cuzent and Gobley, kavahine and methysticin, are the same and correspond to methysticin as it is known today (see figure 3.1). However, the percentage analysis of carbon (C), hydrogen (H), and oxygen (0) given by Cuzent (1861a) for kavahine 5.85% C, 5.64% H, and 28.51% 0) is closer to the composition of didromethysticin (65.21 % C, 5.84% H, 28.95 % 0) than to that of methysticin 5.69% C, 5.15% H, 29.17% 0, calculated in Lebot and Cabalion 1986). The melting point of kavahine, 120-130 C, is also nearer to that of dihyromethysticin (116-118 °C, Winzheimer 1908; 117-118 °C, Borsche and Bodenstein 1929; 118 °C, Joessang and Molho 1970) than to that of methysticin 132-135 °C, Sauer and Haensel 1967; 136-137 °C, Rasmussen et al. 1979; 139-140 °C, Borsche and Peitzsch 1929a; see also Duve 1981). The differences bserved between these figures would be easy to explain if Cuzent had actually obtained and analyzed pure syncrystals, but the 10 °C variation in the melting point of his kavahine indicates that the substance he analyzed was contaminated. Our best guess is that Cuzent's kavahine was a mixture of dihydromethysticin and methysticin."
[http://www.aldbot.com/New_Folder-1/ch3lebot.htm]


Kava: From Ethnology to Pharmacology- Taylor et al. 2004:
"According to Duve and Prasad (1983), there are trends in the deterioration of the major active constituents in both dry powdered root and basal stems. Storage of the samples in screw-capped glass bottles at room temperature resulted in 26, 33 and 55% degradation of the major constituents in the roots and 24, 50 and 48% degradation in basal stems after 22, 36 and 39 months of storage, respectively. Moisture and
temperature are probably the major environmental factors affecting the deterioration of dry powdered plant material. Stability of the active constituents appeared to be dependent on the chemical structure, with dihydrokavain being the least stable and methysticin the most stable (Duve and Prasad, 1983). In addition, stability improves with increasing melting point and the degree of unsaturation. These findings suggest that more polar substances are likely to be stable at room temperature. In contrast, in non-polar molecules like dihydrokavain, the pyrone ring tends to open up to form more polar acidic components which would be readily stabilized by moisture from the storage environment. The identity of the degradation products have not been established but formation of a characteristic off-odor from the samples has been described (Duve and Prasad, 1983), which probably reflects formation of the corresponding acids from the active constituents. Further studies are, however, needed before firm recommendations can be made on storage conditions for powdered kava."
As far as I know, these are all predicted and have not actually been observed.

Boiling points (found from chemical and biochemical sources):
Kavain: 432.64 °C at 760 mmHg
Dihydrokavain: 413±45.0 °C at 760 mmHg
Methysticin: 496.48 °C at 760 mmHg
Dihydromethysticin: 476.1ºC at 760 mmHg
 
Last edited by a moderator:

sɥɐʞɐs

Avg. Dosage: 8 Tbsp. (58g)
Review Maestro
I can't remember exactly but i think they're only destroyed around boiling temp. or something...and the general concensus these days seems to be that hot water helps with kavaloactone extraction.
 
D

Deleted User01

Shakas, I think the old Forum stated the temperature tolerance for Kavalactones but I don't remember what it was. 212F would be off limits for sure. According to the research paper posted by Infraredz, 113F would exstract 25 percent more Kavalactones. But in the old days, everyone would say that hot water would make the Kava taste bad. (Like it already didn't taste bad). So I do mine at 120F to allow for the fact that it will cool down during the 10 minute steeping process and I use coconut water so I don't care about the taste factor.

I'm adding something to this post. The last Melo Melo I made was done with the hotter water. Yesterday I drank about 10oz. of Melo in the afternoon. I was going to finsh the afternoon with some WOW but I never made it. The Melo was more than enough. So now I wonder if I got 25-40 percent more Kavalactones like the study suggested? Just a thought.
 
Last edited by a moderator:

infraredz

BULA!
I found this quote on the old forum:
"About three years ago, a test (using HPLC) was done on boiling the kava beverage (~212F). Loss after a few minutes at that temperature was considered insignificant. Less than 5% of the kavalactones were lost."
[The link is broken, but the quote was from the owner of Hawaiiankava.com]

And:
"This one's more about special lab equipment based extraction so I can't be sure it applies here, but the graph on page 190 (and following pages) shows that, in general, the percentage of extraction increases as temperature increases. Yangonin extraction is essentially 0% until you reach boiling point"
[link seems broken to me, but you could try it: http://144.206.159.178/ft/553/42507/769267.pdf]

And:
"Various authors have suggested that the two compounds isolated by Cuzent and Gobley, kavahine and methysticin, are the same and correspond to methysticin as it is known today (see figure 3.1). However, the percentage analysis of carbon (C), hydrogen (H), and oxygen (0) given by Cuzent (1861a) for kavahine 5.85% C, 5.64% H, and 28.51% 0) is closer to the composition of didromethysticin (65.21 % C, 5.84% H, 28.95 % 0) than to that of methysticin 5.69% C, 5.15% H, 29.17% 0, calculated in Lebot and Cabalion 1986). The melting point of kavahine, 120-130 C, is also nearer to that of dihyromethysticin (116-118 °C, Winzheimer 1908; 117-118 °C, Borsche and Bodenstein 1929; 118 °C, Joessang and Molho 1970) than to that of methysticin 132-135 °C, Sauer and Haensel 1967; 136-137 °C, Rasmussen et al. 1979; 139-140 °C, Borsche and Peitzsch 1929a; see also Duve 1981). The differences bserved between these figures would be easy to explain if Cuzent had actually obtained and analyzed pure syncrystals, but the 10 °C variation in the melting point of his kavahine indicates that the substance he analyzed was contaminated. Our best guess is that Cuzent's kavahine was a mixture of dihydromethysticin and methysticin."
[http://www.aldbot.com/New_Folder-1/ch3lebot.htm]


And (more regarding chemical structure and implications for storage):
"According to Duve and Prasad (1983), there are trends in the deterioration of the major active constituents in both dry powdered root and basal stems. Storage of the samples in screw-capped glass bottles at room temperature resulted in 26, 33 and 55% degradation of the major constituents in the roots and 24, 50 and 48% degradation in basal stems after 22, 36 and 39 months of storage, respectively. Moisture and
temperature are probably the major environmental factors affecting the deterioration of dry powdered plant material. Stability of the active constituents appeared to be dependent on the chemical structure, with dihydrokavain being the least stable and methysticin the most stable (Duve and Prasad, 1983). In addition, stability improves with increasing melting point and the degree of unsaturation. These findings suggest that more polar substances are likely to be stable at room temperature. In contrast, in non-polar molecules like dihydrokavain, the pyrone ring tends to open up to form more polar acidic components which would be readily stabilized by moisture from the storage environment. The identity of the degradation products have not been established but formation of a characteristic off-odor from the samples has been described (Duve and Prasad, 1983), which probably reflects formation of the corresponding acids from the active constituents. Further studies are, however, needed before firm recommendations can be made on storage conditions for powdered kava."
 

infraredz

BULA!
Also:
As far as I know, these are all predicted and have not actually been observed.

Boiling points:

Kavain: 432.64 °C at 760 mmHg
Dihydrokavain: 413±45.0 °C at 760 mmHg
Methysticin: 496.48 °C at 760 mmHg
Dihydromethysticin: 476.1ºC at 760 mmHg
 
D

Deleted User01

The study you downloaded a few weeks ago stated that 113f (45c) was optimal for kavalactone extraction. However, they didn't test extraction at higher temperatures which begs a lot of questions. I can just see us feeding you (since you are the chief scientist here) Kava done at higher temperatures and asking "Are you more Krunked or Less? How about now? (as we feed you another Shell at diff temps)." Not very scientific .....

I wonder what kind of equipment or chemicals can measure Kavalactones? Maybe there is a color test like the one you use on the much maligned Tudie-ish Kavas.
 

infraredz

BULA!
Heh, well thanks but I think we are all scientists in one way or another.

The molecular structures have already been determined, and can be estimated with various sophisticated methods, but there are some general rules that can be used to estimate boiling points in comparing two molecules (branching, intermolecular forces, molecular weight, number of carbons present, surface-area dependence of Van der Waals dispersion among others). This is pretty easy with simple molecules, but stuff like kavalactones are too complex for me. HPTLC could be used to determine the presence of lactones after exposure to various temperatures and Mass spec could be used to determine the masses of lactones & chemical structure of the lactones (already done). The simple, qualitative solvent extract is a very imprecise analysis, especially since we don't know the mechanism behind the color change. I guess a simple (read: ghetto) paper chromatography test could be done with coffee filter paper but the amount of information gathered wouldn't really be of much use (pigmentation is all that comes to mind).
 

Dan

Kava Enthusiast
I have accidentally let my brew start boiling a few times. (Not sure of the actual temperature, but it was bubbling pretty vigorously, if not exactly roiling.)

Anyway, its effects were just as strong.
 
Top