Rosemary EO vs ROE for preventing rancidity & DOS

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earlene

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I've been searching for an answer and either my search parameters just are not specific enough or the answer is too deeply buried to find. In any case perhaps someone here knows the answer or is aware of some studies that compare the two in regards to preventing rancidity and DOS in soap.

I have found studies that attribute this property to the carnosic acid content, but unfortunately not one that compares the two, let alone any that suggest any different usage amounts.

Does anyone here know the answer? I have a lot of Rosemary EO and that is what I have started using, but I just don't know if it is sufficient.
 

Susie

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Rosemary EO is not ROE, nor does it function as enough of an antioxidant to prevent rancidity.
 

earlene

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Rosemary EO is not ROE
No, I know that. Perhaps I was not clear in my question.

nor does it function as enough of an antioxidant to prevent rancidity.
Thank you for your answer. Can you expand upon that?

Have you tried them out side by side for comparison or know of any studies addressing this issue?

Another question I have is based on the following:

Even among different Rosemary Oleoresins avaiable for purchase, I have seen varying concentrations of carnosic acid, and from what I have found that is the pertinent ingredient for preventing rancidity & DOS. I could be wrong, of course, but that is what I gather from what I have read. So when the concentration of the carnosic acid can be so variable in ROE, how does that affect the amount to be used in soaping?
 

topofmurrayhill

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Thank you for your answer. Can you expand upon that?

Have you tried them out side by side for comparison or know of any studies addressing this issue?

Another question I have is based on the following:

Even among different Rosemary Oleoresins avaiable for purchase, I have seen varying concentrations of carnosic acid, and from what I have found that is the pertinent ingredient for preventing rancidity & DOS. I could be wrong, of course, but that is what I gather from what I have read. So when the concentration of the carnosic acid can be so variable in ROE, how does that affect the amount to be used in soaping?
The active ingredients are rosmarinic acid and carnosic acid (plus some related compounds). Whether one or the other is a stronger antioxidant seems to depend on the circumstances. Carnosic acid generally gets the most credit for the antioxidant effect, but I have seen suggestions that rosmarinic acid is the more effective one for soaping applications.

Since the ideal usage rate of ROE in soaping is undetermined (to my knowledge) the variation in carnosic acid content doesn't clearly suggest a change in the usage rate. More generally, ROE has been been very effective in some tests at 0.1% oil weight. Probably you want to stay within some fraction of 1% since ROE can affect the color and fragrance of the soap.

Rosemary EO is supposed to have antioxidant properties as well, but I've never seen a comparison of the two. In terms of research there is much more information on ROE as an antioxidant, and it seems to be preferred in cases where rosemary is used for this purpose in industry.
 

Susie

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There was a thread on here 2 or so years ago about ROE. I am fairly sure IrishLass or DeeAnna had a great answer. But my mind has failed to retain what they said exactly.

I am somewhat confident in saying that whoever it was added ROE to oils that could go rancid as soon as they got those oils rather than to soap itself.

I will try to find it, but I have limited time tonight, and I have to work tomorrow.

ETA: The search does not go back far enough to find 2012-2013 posts by DeeAnna. Sorry.
 
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earlene

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Thank you, both of you for your answers.

I have read posts by Deanna & perhaps someone else also, where she mentioned that she adds Roe to the oils as soon as they arrive.

I'm looking to buy some ROE with my next order of soaping supplies.
 

topofmurrayhill

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Well, obviously I don't know what I'm talking about. Post deleted. Cream or milk -- pick your poison.
 

BlackBoar

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I just got some ROE too and I'm lost on what to do with coconut oil or hard butters. It doesn't really help much with shea or cocoa butter but I guess it's only the liquid oils that go rancid.

If I mix a hard oil with a liquid in an emulsified scrub it might be tricky to come up with a percentage of what actually ends up in the product.

Was this already posted here?
http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf

"If your client base is heavily tilted toward natural ingredients,
using 0.1% of your oil weight in ROE is very likely to
significantly extend your shelf life. If, on the other hand, your
client base is indifferent to the natural/artificial distinction,
the combination of BHT and Sodium Citrate is likely to outperform
ROE as a preservative. "

Never heard of the other stuff.
 
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Susie

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It is usually the liquid oils that tend to go rancid faster than the harder oils. However, please remember that ROE and other additives are typically added to the oils when they are first purchased to prevent the oils from becoming rancid before or shortly after use. Therefore, I would not worry so much about adding the antioxidants to products, just the oils before use. Then you may safely assume that the antioxidant would be at the end of an ingredient list. If you need the amount that remains in a product, you must first figure out how much is in each oil, then how much oil is in each "portion" of product.
 

topofmurrayhill

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I just got some ROE too and I'm lost on what to do with coconut oil or hard butters. It doesn't really help much with shea or cocoa butter but I guess it's only the liquid oils that go rancid.
As Susie said that's right. It would be difficult and maybe counterproductive to melt the hard oils just to add ROE. Unless you master batch, Adding it to the bulk liquid oils is probably what you should do.

Personally I add it to the oils for each batch so that I have the option of leaving it out. That's just me. With ROE and some other antioxidants (this happens when I use SC lard for instance, even if I add nothing to it myself), there's a chemical reaction as soon as you add the lye that turns the batter very orange. The color fades away and doesn't affect the soap unless you've used too much, but it kind of freaks me out anyway. When I want the soap to be as white as possible I leave out the ROE as a precaution and just use a chelator. I also have been using only EDTA with liquid soap.

Probably unwarranted concerns, but as long as I'm going through my oils at a reasonable rate, I like the flexibility. I only use very stable oils.
 

earlene

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The OP mentioned that she knows the difference, but her question about the relative effectiveness is valid. Cream works too.

http://www.academia.edu/6085436/CHE...F_THE_ESSENTIAL_OIL_OF_THE_THYME_AND_ROSEMARY

Thank you, topofmurryhill. That study seems to indicate that the antioxidative effects of Rosemary EO is pretty good as compared to Thyme EO. It also looks like a concentration of 0.5% Rosemary EO, although a bit more effective, was not really significantly more effective than a concentration of 0.25% Rosemary EO. And obviously, both were significantly more effective than nothing added (the control). So it appears that Rosemary EO is effective as an antioxidant at 0.25% concentration, and a bit more effective at 0.5% concentration.

So, unless I am reading this incorrectly, I would add 1.13 grams of Rosemary EO to 16 ounces of oils for the 0.25 % concentration, or 2.27 grams of Rosemary EO for the 0.5 % concentration. Is that correct?

Do you, by any chance, have a link to something similar regarding ROE from which I could garner some sort of comparative data? I've been searching, but all I am finding doesn't quite have the same kind of empirical data as the paper you linked in your above post. I did find one as it related to use in oils for deep frying, but the details given were simply too vague.


N.B. I cannot find any problem adding this amount of Rosemary EO to soap, neither in IFRA standards, which I have to admit I am having a lot of trouble trying to fathom, nor anywhere else. That is unless someone might have an allergy to Rosemary.
 

earlene

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I just got some ROE too and I'm lost on what to do with coconut oil or hard butters. It doesn't really help much with shea or cocoa butter but I guess it's only the liquid oils that go rancid.

If I mix a hard oil with a liquid in an emulsified scrub it might be tricky to come up with a percentage of what actually ends up in the product.

Was this already posted here?
http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf

"If your client base is heavily tilted toward natural ingredients,
using 0.1% of your oil weight in ROE is very likely to
significantly extend your shelf life. If, on the other hand, your
client base is indifferent to the natural/artificial distinction,
the combination of BHT and Sodium Citrate is likely to outperform
ROE as a preservative. "

Never heard of the other stuff.
I would be tempted to use BHT & sodium citrate, based on the findings on their combined efficacy. Sodium citrate is a naturally occuring salt of citric acid. And although BHT does occur naturally in Cytisus triflorus, a shrub in Algeria (link), the synthetically made BHT has a well established record of causing lung tumors. Personally, and this is only me, I don't want to introduce additional risk factors for my lungs at my age (I am 67) so I don't really think I am going to be going this route. Still it is tempting because of the results of this experiment done by Soapsmith.
 

topofmurrayhill

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Thank you, topofmurryhill. That study seems to indicate that the antioxidative effects of Rosemary EO is pretty good as compared to Thyme EO. It also looks like a concentration of 0.5% Rosemary EO, although a bit more effective, was not really significantly more effective than a concentration of 0.25% Rosemary EO. And obviously, both were significantly more effective than nothing added (the control). So it appears that Rosemary EO is effective as an antioxidant at 0.25% concentration, and a bit more effective at 0.5% concentration.

So, unless I am reading this incorrectly, I would add 1.13 grams of Rosemary EO to 16 ounces of oils for the 0.25 % concentration, or 2.27 grams of Rosemary EO for the 0.5 % concentration. Is that correct?

Do you, by any chance, have a link to something similar regarding ROE from which I could garner some sort of comparative data? I've been searching, but all I am finding doesn't quite have the same kind of empirical data as the paper you linked in your above post. I did find one as it related to use in oils for deep frying, but the details given were simply too vague.


N.B. I cannot find any problem adding this amount of Rosemary EO to soap, neither in IFRA standards, which I have to admit I am having a lot of trouble trying to fathom, nor anywhere else. That is unless someone might have an allergy to Rosemary.
Yes your numbers are fine.

I don't have a link or document that you wouldn't find by googling 'antioxidant effectiveness of rosemary extract'. Going back to your original question, I don't think that includes anything you could use to come to a conclusion about the relative effectiveness of EO versus extract.

So one problem with using EO is that it could be less effective. The extract can be as protective as synthetic antioxidants, which is a high bar. The second problem is that it might be useless. You would not only want to compare the two in the same experiment, but you would want to test the EO in soap. Antioxidants that work in one application might not work the same way in another. Vitamin E is an antioxidant, but our best information right now is that it might protect oils but not soap.

So your best bet would still be ROE.
 

earlene

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Yes your numbers are fine.


So your best bet would still be ROE.
Thank you. It is on my purchase list for my next online order.

I plan to do some experimentation of the 2 side by side just for my own information. I appreciate your help. So far I haven't found anything useful on Rosemary Extract or ROE in my searching, but maybe I will at some point in the future. Either way, I do plan to do the experiment with some of my recipes to see how they compare (once I have the ROE, that is.)
 

penelopejane

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Rosemary EO vs ROE for preventing rancidity & DOS

ROE does not fragrance your soap.
Some people are allergic to Rosemary EO because it is an essential oil.
Not sure if they'd also be allergic to that smaller amount of ROE.
 
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topofmurrayhill

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Thank you. It is on my purchase list for my next online order.

I plan to do some experimentation of the 2 side by side just for my own information. I appreciate your help. So far I haven't found anything useful on Rosemary Extract or ROE in my searching, but maybe I will at some point in the future. Either way, I do plan to do the experiment with some of my recipes to see how they compare (once I have the ROE, that is.)
In case you haven't seen this.

http://cavemanchemistry.com/DreadedOrangeSpot-Dunn.pdf
 

earlene

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Yes, thank you. I have it bookmarked as a reference and plan to refer back to it when I get the ROE and do the side by side experiment.

I was thinking I would do it using one of the oils that develops DOS quickly on its own. I have 2 or 3 single oil soaps I did last year that have turned quite orange, so I'll choose one of those oils. The worst one is Crisco, and even though it is not really a single oil, it might be my choice for this experiment.
 

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