Freezing henna paste = Instant(ish) dye release?

[akilina]

Last time I mixed henna I mixed it in warmish water and let it sit maybe for a few hours...maybe less I can't even remember and then I just threw it in the freezer. It has been maybe a week since then and I plan to use this henna sometime this coming week. In the past I have froze henna after letting it "get ready" for about 12 hours with even better stain after freezing-thawing. I hope this mix comes out fine...I have been sort of nervous about it

[cmg]

As for the dye release theory, no one really knows how henna works (no scientist has actually researched it in a real lab).

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

[cmg]

Additional info:

In combination with metal salts, fex containing iron, fibres can recieve not only beige-ish and reddish-brown stains, but also blueish gray stains from only the henna (no indigo).

/ CMG

[cthulhuapproved]

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

Wow, this is awesome! Thank you for sharing this!!

[Anywhere]

I may be mistaken but I feel like most people seem to be imagining it as being that if you mix henna and put it in the freezer it will instantly freeze the very second you close the freezer door.

The mixture will take a while to cool off, so it can still "dye release" the "regular" way while sitting in the freezer.

[cthulhuapproved]

I can only speak for myself as a..."frozen paste advocate," for lack of better phrasing, but I definitely agree that the time from mixing to actual freezing could very well account for the dye release when doing this (as opposed to my other 'hypothesis'). What I find confusing, though, is the reports of those who have left henna in the fridge to dye release, and have found that it can take days. This seems to suggest that it would require a similar amount of time sitting in the freezer, pre-freezing, for it to release enough to be usable.

However, in my experience, this is not the case. I actually divide my batches up into smaller containers than I mix them in specifically to get them to freeze in a reasonably quick time frame, and they are ready to go the moment they thaw enough to be workable, as evidenced by the prominent stain left on my wrist at that point. (Actually, I'm prone to impatience and there are sometimes still some frozen chunks in the mix when I try to apply it, if that helps to describe how cold it still is at this point.) The next time I mix up a batch, I think I will put half in the fridge and half in the freezer, and then compare the two after the freezer portion has thawed. If it is true that the paste is just dye-releasing before it has a chance to freeze, then it would stand to reason that the paste in the fridge should provide an equal amount of staining.



Either way, though, the main reason why I appreciate this method so much is the convenience---since I often have a hectic schedule, not having to worry about when the paste will be ready (or whether it will demise before I get a chance to use it) is reason enough for me to continue doing this, regardless of lack of legit scientific evidence! Not to mention, it only took four or five ~2hr applications prepared this way to get my hair to my desired point of near-saturation. So I'm pretty inclined to just chalk it up as "if it works, it works!" and carry on accordingly!

[cmg]

If it works, it works! Absolutely

But for the sake of understanding and learning from it, how exactly do you prepare your mixes? Have you ever done a batch and compared an unfrozen portion with a frozen one etc.?

/ CMG

[Unicorn]

I may be mistaken but I feel like most people seem to be imagining it as being that if you mix henna and put it in the freezer it will instantly freeze the very second you close the freezer door.

The mixture will take a while to cool off, so it can still "dye release" the "regular" way while sitting in the freezer.

I also freeze my henna, no not making this assumption. I assume that any difference is only from the point of the mixture actually freezing. I do let it sit for an hour or two, so it's already cold when it goes in the freezer. Prior to freezing I used to let it sit for 2-3 hours, then apply for 4. I still apply for 4hours and definitely get a better colour from the frozen henna. I have some grey hairs at my temples, it does make quite the difference to these hairs.

Slightly different topic, but I also do this when I prepare homemade vegetable soup (including lentils/beans). I make a huge batch, using some over a couple of days and freezing the remainder. The soup that has been frozen is always much thicker that that which has only sat in the fridge. Enough that I often need to water it down. Presumably the same process is the cause of the thickening.

Unicorn

[cthulhuapproved]

If it works, it works! Absolutely

But for the sake of understanding and learning from it, how exactly do you prepare your mixes? Have you ever done a batch and compared an unfrozen portion with a frozen one etc.?

/ CMG

It's really a pretty unceremonious process: I brew some chamomile tea and then I usually wander away and forget about it for awhile. When I finally add it to the henna powder, it's usually a little warmer than room temperature, but not what I'd consider 'hot' by any stretch. Then I just mix the two together in a large bowl and then separate it into separate smaller containers, which go immediately into the freezer. (The original purpose of this division was simply because I didn't have enough space in the freezer at the time for the actual mixing bowl. )

That usually takes place the night before I plan to henna, so the following morning I take however much out that I need, and leave it on the counter until it is thawed. If I'm home for it, I stir them frequently to keep the center from remaining frozen while the outside thaws. Then I just put it straight on, leave it for 2 hours or so, and rinse. Overall, pretty unexciting!

The first time I tried freezing it was definitely just an experiment---I had noticed that the general consensus seemed to be that, if leftover henna paste was frozen and used later, it typically stained better afterward. Then I read about someone supposedly getting dye release directly from freezing, so the next time I hennaed I tried it out, and since it was crazy convenient and actually worked, I just kept on doing it! Of course, I've only been doing this for a few months, so it could very well turn out that something else is going on that I'm just unaware of, or that there is a magical leprechaun inside my freezer secretly infusing my paste with mysterious leprechaun hair color...

I haven't tried freezing part of a batch and comparing it to an unfrozen portion yet, but I plan on trying it out this summer!

[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)