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Discoloration during stability
Hi,
I was really bummed to discover that my beautiful light blue emulsion turned greenish grey during elevated stability testing (2 weeks), and also less but still noticeable at RT after 3 months.The same batch without Blue Tansy (and other earlier iterations without Blue Tansy slightly yellowed at RT after 6 and 12 months, and yellowed more at elevated temp. So it may not be the Blue Tansy, that just makes the color more ashen.
My oil phase is 15% (Murumuru, Babassu, Brassica Alcohol, Blueberry and Pomegranate Seed Oil, 0.5% Mixed tocopherols) and 2% Heliosoft + 1% Siligel. Water phase is distilled water, glycols, tremella and 1% Inulin). It’s chelated with Sodium Phytate 0.2%). pH 5.2- 5.3. Preserved with Germall Plus.
My guess is Murumuru (other iterations without it seemed slightly less yellow), the PUFA oils, Inulin?
No change in smell.
What are your thoughts?
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30 Replies
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Let’s wait what the adults say, but lecithin can darken with elevated temperatures, and you have it in Heliosoft and Siligel, so maybe that’s the cause.
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@grapefruit22. YES! I think that’s entirely likely.
But I don’t want to change my emulsifying system, so what does that mean for stability? -
Blueberry oil is also sensitive to heating. How much have you added?
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@grapefruit22: I’ve got 2%. I know those Polyunsaturated oils are tricky. Pomegranate also has a high Iodine value (152 ish I think), but are these at 2% and RT a culprit? Maybe it is the cumulative effect of a few things: lecithin, these guys, something else…?
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Just for giggles…and knock-outs…. do you have TSGD/GLDA?
Try a formula subbing the sodium phytate with this.
I have learned…there are fewer possible issues with this chelate.
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@Graillotion: I will try that. Thank you for the suggestion.
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It is not at all uncommon for emulsions made with oils such as blue tansy to change color when subjected to long-term stability tests. And, many will change color eventually at RT turning an ugly grey or brown.
You might consider making a sample with and w/o blue tansy and put both in the oven to confirm.
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Chamazulene, the blue pigment in blue tansy EO, is fairly unstable and will most likely contribute to colour change.Are the oils and butter highly refined or unadulterated/vergine?Once one ingredient starts oxidising there’s a fair chance that it sets off an avalanche (my guess is that lecithin will be part of it). From personal experience, lecithin browns faster than highly unsaturated oils at elevated temperatures. -
@MarkBroussard & @Pharma. Thank you both for your comments.
@MarkBroussard: I put some close iterations of this emulsion (without Blue Tansy) in the incubator at 45 C last year and they yellowed, and developed a slight pungent scent. Same batches at RT had no scent change and yellowed far less, even at 12 months.
@Pharma: Good question: the Organic Babassu was refined, but the Murumuru was virgin, unrefined.
I should mention that the Blue Tansy at RT after 3 months in a completely opaque white bottle still turned slightly, into an unpleasant grey, though far less than the oven.
So, it seems then that Blue Tansy is one of the culprits.
I will try refined Murumuru, or just swap it for something else. I noticed the iterations with Myrica wax instead of Murumuru didn’t change color much at all. Or maybe use Mango butter instead if it’s less prone to oxidation?
So maybe the oven when it comes to this emulsion is not a super accurate indicator, but is it a Fail? Is the yellowing a sign of instability? Without a peroxide value I can’t really tell if it crossed over to the dark side…
How do I shore up my anti-oxidant system? What type of vitamin E is best to use and at what percentage? Combine it with some ROE, as @Graillotion suggested in a different Post?
If it’s not a matter of instability, I could mask the yellowing by adding 2% Sea Buckthorn…
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The problem you have is that the compounds that give color to Blue Tansy and Seabuckthorn are not long-term stable in the presence of water. So, if your cream that is initially light blue turns grey, I would consider that a fail. Your base emulsion is likely stable, but not the product as a whole. In an emulsion, Blue Tansy will turn grey and Seabuckthorn will turn brown. Blue Tansy and Seabuckthorn are more appropriate to give stable color to anhydrous systems.
If your objective is to color your emulsions where the colors will be more long-term stable you’ll have better results using Malachite Extract or Copper Tripeptide-1 for blue and Cyanocobalamin (Vitamin B12) will give you a pink color.
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Hi Can I ask what is the purpose or function of the Blue Tansy EO in your cream? Could you use another EO like Chamomile or even Bisabolol if it is soothing properties you are after (or are these too expensive for your purpose compared to BT?). Not sure why the cream would need to be blue especially if intended for facial use.
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Pharma said:Chamazulene, the blue pigment in blue tansy EO, is fairly unstable and will most likely contribute to colour change.Are the oils and butter highly refined or unadulterated/vergine?Once one ingredient starts oxidising there’s a fair chance that it sets off an avalanche (my guess is that lecithin will be part of it). From personal experience, lecithin browns faster than highly unsaturated oils at elevated temperatures.
Can lysolecithin darken at elevated temperatures similar to lecithin?
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grapefruit22 said:Can lysolecithin darken at elevated temperatures similar to lecithin?Yes, I’m afraid so
. Hydrogenated lecithin is more stable but still on the fragile side of things.Personally, I don’t like heat testing too much unless your product acutally experiences such temperatures during its life. Every ‘speed test’ used to predict long term stability has to be evaluated for its usefulness for any given product. Emulsion stability (physical integrity of the mixed water-oil system) at elevated temperatures is okay to use as predictive parameter whilst chemical stability might indicate degradation although there might not be any. Also, colour (pigment formation) often shows no linear correlation with degradation.As antoxidants use ascorbic acid or ascorbyl palmitate (depending on what you want to protect) and tocopherol. Rosemary extracts can be a good addition (a rosmarinic acid rich version would be best in conjunction with ascorbic acid whilst carnosic acid/carnosol rich extracts would be my partner of choice for ascorbyl palmitate). If it’s not an issue with your philosophy, dithionite or metabisulfite can help as well (either as substitute for ascorbic acid or in addition to it). -
@MarkBroussard. Thank you for the suggestions! I ordered some samples form UL prospector to try the malachite and the cyanocobalamin. Looking forward to trying them. Unfortunately the B12 is $4800/kg!!! So these would not be raw materials I could work with beyond the UL samples.
I did come across these raw materials:
Micronized cranberry powder with fine particle size 97%<200 µ.
Also Pigment Blue NC63 (Sepiolite, Indigofera Tinctoria Extract) which is supposedly photo-stable. They are both dispersible, not soluble in either water or oil.
Would these maybe work? Powders in emulsions make me really nervous though. I’m concerned they would interfere with the matrix and with preservation.
@Squinny: Thank you for your suggestions. The BT is both for soothing, but mostly the color. The cream is a lovely light blue, much more fun than plain white.
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As mentioned above…I use MT-E, ROE high in carnosic acid, and ascorbyl palmitate, and sans the high temp testing…product keeps color for a year, in a dark glass jar.
It is a 54-ingredient pain cream…so there is the possibility that other factors are at play.
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Campo Research has some plant extracts that are used as colorants and are stable.
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Just as a caution, it is not legal in the US to use most plant extracts as color additives. And saying you add an extract for some other benefit & the color is just a happy side-effect is also not legal according to the CFR.
“For a material otherwise meeting the definition of color additive to be exempt from section 721 of the act, on the basis that it is used (or intended to be used) solely for a purpose or purposes other than coloring, the material must be used in a way that any color imparted is clearly unimportant insofar as the appearance, value, marketability, or consumer acceptability is concerned. (It is not enough to warrant exemption if conditions are such that the primary purpose of the material is other than to impart color.)“
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Perry said:Just as a caution, it is not legal in the US to use most plant extracts as color additives. And saying you add an extract for some other benefit & the color is just a happy side-effect is also not legal according to the CFR.
“For a material otherwise meeting the definition of color additive to be exempt from section 721 of the act, on the basis that it is used (or intended to be used) solely for a purpose or purposes other than coloring, the material must be used in a way that any color imparted is clearly unimportant insofar as the appearance, value, marketability, or consumer acceptability is concerned. (It is not enough to warrant exemption if conditions are such that the primary purpose of the material is other than to impart color.)“
It’s interesting. But what if someone really wants to use Copper Peptide for its functionality? In such a case, would the color of the product have to be hidden somehow, for example, by using an opaque packaging?
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No, Copper Tripeptide-1 has a legitimate function as a cosmetic ingredient. That’s why it is best to use cosmetic ingredients for this purpose.
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@Perry I thought using it for other benefits with color as a side effect was ok. Thank you for clarifying.
So what do yo do as a formulator if you want to create non-white products?
Where do the Campo Research natural pigments fall?
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@Perry Do you have any idea how that stupid regulation came to existance? I mean, there are hundreds of more important things which could/should be regulated in cosmetics and that regulation isn’t even protecting customers.And how would one prove (or disprove) the part you put in bold letters? From a practical point of view (no one is likely to double-check), one could simply add traces of an approved colour and use a plant extract or similar to do the real job instead…A bit OT: choline salts and their esters are currently prohibited in cosmetics for bogus reasons (dating back nearly 50 years, if I’m not mistaken) whilst similar compounds, some of which totally artificial and poorly tested, let alone GRAS food supplements, are seemingly okay to be added.Like with so many things, legal decisions are too often biased by lobbying and political ploys (by people who have not the slightest education or knowledge thereof) than based on scientific and logical reasoning.
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This is primarily an issue for people who desire to impart color to a product, but don’t want to do so using FD&C dyes. I agree with you, how would someone prove that the ingredient imparting color is or is not being used for some specific cosmetic functional purpose. Best if you can justify a legitimate reason for including the ingredient. I think that regulation came out of the FDA’s Department Of Stupid Rules.
@Anca_Formulator … look over the IL of the Campo Research products and see if you can come up with a legitimate functional cosmetic rationale for their inclusion in your products.
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@Pharma - I’m not certain how it came to be but I do know that one of the primary reasons the FDA was created was because people were getting injured by using color cosmetics. (Blindness & lead poisoning among other problems). So, color additives were targeted and became the most regulated of any ingredient used in cosmetics in the US. Interestingly, they followed the “precautionary principle” starting with the idea that all color additives are unsafe unless proven otherwise.
How is this enforced or proven? I’m not really sure. Ultimately, the FDA (or a consumer/competitor) can sue you in court & you’d have to prove that you weren’t breaking the law. Good luck!
People could likely get away with violating the regulations in the same way that people get away with speeding. You can do it for as long as you don’t get caught. Doesn’t seem like a good idea if you are trying to build a brand. For this reason, it is just easier to stick with color additives that are listed on the FDA’s approved list.
@Anca_Formulator - you stick with using color additives that are on the FDA approved list. Specifically, the ones here.
As far as Campo Research natural pigments go, I don’t know. There are some approved natural ingredients that can be used as color additives as per the FDA. But you have to remember, Campo is not on the hook for legal problems if you use their ingredients illegally. The cosmetic producer is the one who will get in trouble, not their suppliers.
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It is funny to me that people complain about how minimally the US cosmetic industry is regulated, but in the two areas where there are significant, clear regulations (color additives and sunscreens) those same people try to get around the regulations.
If your intent is to use an ingredient for the color it gives, it is a violation of regulations to use the ingredient, period.
“It is not enough to warrant exemption if conditions are such that the primary purpose of the material is other than to impart color.”
I encourage all commercial formulators to follow the regulations. You may not agree with them but the legal risk is real. -
Pharma said:grapefruit22 said:Can lysolecithin darken at elevated temperatures similar to lecithin?Yes, I’m afraid so . Hydrogenated lecithin is more stable but still on the fragile side of things.Personally, I don’t like heat testing too much unless your product acutally experiences such temperatures during its life. Every ‘speed test’ used to predict long term stability has to be evaluated for its usefulness for any given product. Emulsion stability (physical integrity of the mixed water-oil system) at elevated temperatures is okay to use as predictive parameter whilst chemical stability might indicate degradation although there might not be any. Also, colour (pigment formation) often shows no linear correlation with degradation.As antoxidants use ascorbic acid or ascorbyl palmitate (depending on what you want to protect) and tocopherol. Rosemary extracts can be a good addition (a rosmarinic acid rich version would be best in conjunction with ascorbic acid whilst carnosic acid/carnosol rich extracts would be my partner of choice for ascorbyl palmitate). If it’s not an issue with your philosophy, dithionite or metabisulfite can help as well (either as substitute for ascorbic acid or in addition to it).
Thank you, your knowledge is tremendous.
I’m asking about it because I like to use Ecogel (a product similar to Siligel, but with lysolecithin instead of lecithin) for thickening and I was wondering if it could cause similar problems with darkening.
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