Freezing henna paste = Instant(ish) dye release?

[Tisiloves]

I'm defrosting the second half of a henna batch, whilst not the best control, I'll get back to you witth the results re:stainage (sorry, it's already started dye release)

Much stronger stain, for dye release times I'll have to experiment with the next lot.

[Katze]

Oh boy, that is not true. There is alot of research. Even the various molecules in various stages of the dye process are subject to patenting. Processes for extraction of Lawsone have been patented. The Lawsone molecules have also been synthesized. The henna dye releases from the plant matter thru acidic (chemical) hydrolysis or enzymatic hydrolysis (which is faster). I hope I spelled it right in english.

Some people think that acidic solutions are required for the dye release, but this is wrong. Besides the scientific chemical research there is also field research that showed that acidic solutions are not required for dye release.

Hydrolysis might entail that the dye is already there in the plant matter, ready for usage as soon as it was released out of the broken down cell walls. Several research reports testify to that. The dye is said to be present in dry leaves at concentrations from 1,0 - 1,4 %. The roots also contain red colouring matter, as well as other parts of the plant. The flowers contain ß- and a-Ionones, which are related molecules. There are several crystalline and other compounds in various parts of the plant, fex in the bark as well.

Further research has proven the simple view of the pre-existing dye, with only leaves and roots being of interest, to be wrong though. There are several stages of the dye before it can actually dye, though aquiring a water solution that dyes is fairly easy. The dyeing capacities are not durable though.

It easily gets destroyed by sunlight, air and so on (oxidizes). The dye molecule is called 2-hydroxy-1,4-naphtochinone (HNO, Lawson, C10H6O3). There are also many synonymes. The plant holds a pre-dye substance (glycosidic precursor) called dihydrolawsone glucoside, which is converted into the dyeing molecule in the waterbased paste after the water had contact with crushed leaves (especially the petioles). Vitamine C naturally occurs in the plant and can react with the Lawsone-molecules and create a stable vitamin C conjugate that is also water soluble. Also different oxidizing processes can occur in the molecules, already present in the hair. Henna dyes protein fibers well, like hairs of humans or animals which contain keratine, but also silk, which is also a protein fibre. The dyeing process can be enhanced with alkaline substances (mordents such as tea tree oil fex).

Traditionally henna has a well established place in folk medicine. But henna plays a big role in various fields of medical research in modern research as well. For example concerning the role of vitamin C: The oxidized form of lawsone has chemical reactivity similar to oxidized lipid (fat) compounds produced under conditions of oxidative stress. These oxidized lipids can lead to oxidative damage in the body, especially to DNA and to proteins. These previously unrecognized properties of Vitamin C can be of interest for comparison to what happens with C vitamines in human bodies.

Just an example of various methods of extracting dye out of henna plant matter (This is actually from late 2011):
http://sphinxsai.com/Vol.3No.4/chem/...944%29OD11.pdf

/ CMG

This is really interesting! Thanks a lot! I will have to show this to DH (a chemist) when we get time.

You mention oxidizing, and that acidic liquid doesn't do anything. These are both backed up by my 16 years of playing with henna (for skin). I recently got 'convinced' to try lemon juice again and got WORSE stains than with hot water.

The one thing that I have never seen is a description of what happens, chemically, to the henna stain after the paste is off. Most hair henna users rinse their hair; most skin henna clients do not. I have noticed a radical difference if the henna design (on skin) does NOT get wet - whatever is happening when the keratin is being dyed seems to get stopped when water hits the area.

My DH told me that in order to really understand how henna stains skin, we'd have to measure pH and hormone levels of the people having henna applied, ambient air temperature and humidity, and MANY other factors which his lab is not equipped to do. But the info you've shared is more than I have seen together from a *reliable* source (there are internet henna sites which I do not consider to be reliable; PM me for details) and is MUCH better than much of the speculation and folklore surrounding henna. Thanks!

[cmg]

You mention oxidizing, and that acidic liquid doesn't do anything. These are both backed up by my 16 years of playing with henna (for skin). I recently got 'convinced' to try lemon juice again and got WORSE stains than with hot water.

You're very welcome.

When it comes to the issue lemon or not lemon, the differences are differences in tradition, not in effect (on hair). There are so many factors at play, so any one occasion for any one person is not representative. And everyone swears their method is the best Until I realized the acidic liquid was only delaying the dyecolor, I could have sworn the water-only method was the stronger one. And so do my indian friends etc. And I have been doing henna on hair since the sixties.

While using water you have to get the right timing though. It easily demizes. With acidic mixes the operating window is longer which makes it easier to use at its maximum potential. I am sure this plays an even bigger role when doing henna for skin art. I suppose you perhaps make big batches and it has to be prepared and stored in a controlled manner so it doesnt get spoiled.

The one thing that I have never seen is a description of what happens, chemically, to the henna stain after the paste is off.

I'm sure I have somewhere. I will try find this and if there is a link to it I will post it here.
(EDIT: Or perhaps you meant on skin?)

My DH told me that in order to really understand how henna stains skin, we'd have to measure pH and hormone levels of the people having henna applied, ambient air temperature and humidity, and MANY other factors which his lab is not equipped to do.

I have read some tests done with henna on skin, that speculated in what the henna attaches to in/on the skin. The test tried to identify several DNA components (proteins) to see if they were there or not. I am sure your DH is right. Hormone levels, skin pH, sebum and moisture levels etc. must play a role here. But mostly I think it is a matter of using some mordent (essential (?) oils) to make it stick to the outer layer of the skin (This also affects the darkness of the color). I dont know so much about henna tattoos so my wisdom ends here.

/ CMG

EDIT:
I have a problem with calling it essential oils. In german and swedish for example, this stands for fatty acids, not scents. The scent is called "etheric oil". I looked it up and it seems to be correct in english to call it "essential". Abit confusing for me. I have to figure out what people are really talking about sometimes.

[Bat]

Freezing it can last a year+ but just refrigerating it lasts 2 days

[Priska]

Katze was just talking about a lot longer release times like 3-4 days. I'm just interested if that long dye release time would give even better dye result. When I started to use12 hours release time, my results got lots better. Maybe I just must test this myself. I just wouldn't like to spoil the whole process and get my henna demised... but yes, I could try with smaller amount.

[TatsuOni]

Katze was just talking about a lot longer release times like 3-4 days. I'm just interested if that long dye release time would give even better dye result. When I started to use12 hours release time, my results got lots better. Maybe I just must test this myself. I just wouldn't like to spoil the whole process and get my henna demised... but yes, I could try with smaller amount.

I dye my nails with henna. As long as it's kept in a tight container I can use it for more than a week without any problem. I've once used it after 15 days.

I do add vinegar, sugar and essential oils to the nail blend. But no vinegar or sugar to the hair blend.

I've been meaning to try and see if there's a difference between the blend that I use for my nails and hair. Probably the next time I touch up my roots. I'll keep both stored the same way and do skin a skin test every other day or so, to see how they stain and for how long.

[Priska]

I dye my nails with henna. As long as it's kept in a tight container I can use it for more than a week without any problem. I've once used it after 15 days.

I do add vinegar, sugar and essential oils to the nail blend. But no vinegar or sugar to the hair blend.

I've been meaning to try and see if there's a difference between the blend that I use for my nails and hair. Probably the next time I touch up my roots. I'll keep both stored the same way and do skin a skin test every other day or so, to see how they stain and for how long.

Does the dye result stay same all the time?

[TatsuOni]

Does the dye result stay same all the time?

It's the best after two or so days and up to a week. Then it looses in effect slightly, but not massive. But I've also found some differences in how many times I open it and room temperature. But I have to do proper testing to really say exactly how potent it is during what time.

[Priska]

It's the best after two or so days and up to a week. Then it looses in effect slightly, but not massive. But I've also found some differences in how many times I open it and room temperature. But I have to do proper testing to really say exactly how potent it is during what time.

So the best level is achieved already in 2 days, but I should be able to get good results also after that. Thank you for telling how it has worked with you
I wonder where this claim comes from, that it demises so quickly... But maybe different henna batches/brands/trees act differently Or then that happens if you keep it all time in an open box in warm climate.

[tuanyiji]

I dye my nails with henna. As long as it's kept in a tight container I can use it for more than a week without any problem. I've once used it after 15 days.

I do add vinegar, sugar and essential oils to the nail blend. But no vinegar or sugar to the hair blend.

I've been meaning to try and see if there's a difference between the blend that I use for my nails and hair. Probably the next time I touch up my roots. I'll keep both stored the same way and do skin a skin test every other day or so, to see how they stain and for how long.

Speaking of which, I also froze my henna nail dye and reapplied it after two weeks, still worked very well, the stain lasted a long long time, I first did it in February 2nd and then 15th, I never did it again, and now in September, the very tip of my toe nails still had the orange evidence of that henna stain, OMG that’s over half a year!