Water/Lecithin Separation

Hi all,

I have a formula for an ingestible that contains Water, Oil, Lecithin, and Xanthan Gum

Water: 79.275%
Oil: 19.1%
Lecithin: 1.25%
Xanthan Gum: 0.275%
Potassium Sorbate: 0.1%

The emulsion separates into a clear water layer below, with a lecithin/water/oil emulsion above. And this top layer has shown mold growth which is the primary problem.

Any ideas? It seems the Potassium Sorbate is not being effective (or maybe the preservative has separated away, although if that were the case, I don't know why the top layer wouldn't be anhydrous and thus wouldn't be able to grow mold?)

Thanks in advance. I appreciate any input!

Jack

Comments

  • BelassiBelassi Member
    I've never used lecithin but I should think that the proportion of oil to emulsifier is way out of whack. Secondly I see no pH adjustment, it's almost certain that the pH >5.5 which means the tiny amount of sorbate is not going to be even active. And lecithin is perfect food for bacteria and yeasts. You need to rethink this system.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • Can you provide more details?
    - what else is in it?
    - pH
    - method used to emulsify
    - is this kept refrigerated?
    - type of oil
    - type of lecithin
    - how long before it separated?

    Maybe this can help others come up with better ideas. Researching lecithin (for cosmetics) I found that it requires high shear emulsification. 
  • PharmaPharma Member, Pharmacist
    Lecithin (as mentioned, there's a ton of different products under that INCI) is tricky to work with and each requires its own production procedure which has to be followed quite precisely.
    And yes, your preservation ain't one.
  • edited July 2
    Hey all,

    Thanks for your input.

    Details: I am using this liquid lecithin in the tests.

    Process:

    1. Add Lecithin and Xanthan Gum to water.
    2. Heat
    3. Blend together.
    4. Add oil while blending.
    5. Add preservative when cooled.

    Initially the emulsion seems strong. There is separation over the next few hours (photograph attached):

    Then, after a few days mold growth is detected.



    @Pharma what ingestible preservative would you recommend in this system?

    @Belassi What oil/emulsifier balance do you recommend? I don't need as much oil as this system contains, but I based it on a successful study that I had found in research. I believe I need less than 10% oil to put the flavoring and other essential oils into the system.

    For what it's worth, I have a version with orange essential oil and peppermint essential oil. The peppermint had growth much more quickly than the orange. I assume this is the PH issue you are talking about.

    Thanks all.



  • EVchemEVchem Member
    potassium sorbate can only help protect your product when the pH is 5.5 or lower. You need to add citric acid or the like and check the pH of your final product. Also you probably want to do more like 0.2-0.3% potassium sorbate, and couple it  with maybe sodium benzoate 
  • EVchem said:
    potassium sorbate can only help protect your product when the pH is 5.5 or lower. You need to add citric acid or the like and check the pH of your final product. Also you probably want to do more like 0.2-0.3% potassium sorbate, and couple it  with maybe sodium benzoate 

    Thanks for the input. I will start experimenting with this. Is there another substance I can use to lower the PH that won't affect taste?
  • PharmaPharma Member, Pharmacist
    Try to add lecithin to water and wait for several hours at room temperature so it can hydrate properly. However, the data (or rather lack thereof) you provided for your liquid lecithin aren't helping.
    Regarding preservation: I'd use a blend. Depends if you want it 'natural', 'alternative', or are okay with 'traditional'... traditional would give you most safety.
    pH won't affect taste (you're eating your emulsion?) but it might affect emulsion stability (to better or worse remains to be seen).
  • edited July 2
    Pharma said:
    Try to add lecithin to water and wait for several hours at room temperature so it can hydrate properly. However, the data (or rather lack thereof) you provided for your liquid lecithin aren't helping.
    Regarding preservation: I'd use a blend. Depends if you want it 'natural', 'alternative', or are okay with 'traditional'... traditional would give you most safety.
    pH won't affect taste (you're eating your emulsion?) but it might affect emulsion stability (to better or worse remains to be seen).

    @Pharma, thanks for your input. I'll try some different versions of Lecithin and see if there's one with a lot more information.

    And yes this emulsion is a sprayable edible product, which is why I had the question about Citric Acid affecting flavor.

    Also, the product being edible informs the answer to your preservative question. It has to be edible. Other than that, I don't have a preference.

    Thanks!
  • PharmaPharma Member, Pharmacist
    Add also benzoic acid as an antibacterial compliment to sorbic acid.
    Now, citric acid won't have a flavour but the taste of a slightly acidic product will be different to a pH neutral to slightly alkaline one.
    It has to be acidic or both these preservatives won't work. Also, a low pH increases microbial stability.
    Also, it is recommended to add a chelate. Citric acid won't likely be strong enough... maybe add phytic acid or sodium phytate (which is also alkaline = more citric acid required)?
    You could also add something to lower water activity such as glycerol or ethanol at sufficient %.
  • chemicalmattchemicalmatt Member, Professional Chemist
    That is not pure lecithin but the typical 55% dispersion in soybean oil, so your activity level is less, and this should be a 2-phase procedure not a one-pot. Double it and add your oil to that (you have a o/w emulsion here) at 80C, then slowly add to the water phase. IF you can live with a little high fructose corn syrup or just sucrose or another saccharide to your water phase, that will help matters along. Like Pharma said: not all lecithins are the same. The phosphatidyl choline: phosphatidyl serine content makes a HUGE difference and I think that website source is unaware of that. (They are also marking that product up by 400% more than commercial.) As for preservation: have you tried adding vodka?
  • edited July 2
    Thank you gentlemen. I will look for pure lecithin.
    Matt: Apologies, we do use two pots and heat them both, and we are currently adding the oil to the water while being blended.
    So Pot 1: Water, Lecithin, Xanthan Gum
    Pot 2: Oils
    Pot 2 into Pot 1. (Oil into Water while agitating)

    The sweetener in this product is Stevia. There's another formula I am trying with Sucralose, though.
    The initial emulsion (and after being shaken/agitated) is great, tastes great, hits all the marks. It just breaks and grows mold (lol). I will get my hands on different lecithin and will also play around with the pH to get it acidic and go from there.

    Thanks all.
  • AbbotAbbot Member
    I use an Ultrasonic blender @70F degree to get the Lecithin in solution.  Comes out well.  just a guess, oil content too high to suspend. Add tween?
  • PharmaPharma Member, Pharmacist
    @Abbot Who has an ultrasonic blender? Sure, it works wonders with lecithin... and yes, tweens at about 1/10 of lecithin can greatly increase success rate. I wonder if polyglycerol esters would work as neatly, too.
  • natiyo123natiyo123 Member
    Surfactants can be tricky to work with, learned from my own experience...

    I would try this process instead if I were you:

    Process:

    1. Add Xanthan Gum to water.
    2. Heat
    3. Blend together.
    4. Blend Oil + lecithin (oily phase)
    5. Add oily phase while blending.
    6. Add preservative when cooled.
  • @Abbot, thanks for the recommendation. Any ultrasonic blender recommendations?

    Also, I can lower the oil content if that will work better. I only need about 2%-3% oil... I was following a study that was done, that's why my oil was higher. But it can be much lower. The flavoring and hemp oil marketing being done for this product can be satisfied with under 3% oils.

    @natiyo123, thanks for your recommendation. I'll give that process a try.

    @Pharma, which tween would you recommend I start experimenting with? Also, tweens are edible, correct? (I will research this of course).

    I am awaiting my lecithin to be delivered. Thanks for the assistance everyone, I will post updates as I make progress on this formulation. (Two separate formulations, really).
  • PharmaPharma Member, Pharmacist
    Edible... well, I wouldn't call them edible but some are approved food additives. I did use Tween 80 though it all depends on the type of lecithin you're using, I used highly purified PC derivatives. Hydrogenated lecithin might work better with Tween 60 (that's just a speculation!).
    Anyway, the reason Tweens are a good partner is mostly due to the sorbitan moiety and all Tweens have that, Tween 60 and 80 align better with the fatty acid chains of lecithin than the shorter chained Tween 20 and Tween 80 is liquid because it's made from oleic acid and that pairs even better with non-hydrogenated lecithin.
  • BelassiBelassi Member
    You might try potassium glycrrhizate instead of stevia, about the same percentage. It has the property of forming certain types of emulsion.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
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