Home Cosmetic Science Talk Formulating Serum turns dark

  • Serum turns dark

    Posted by izzie01 on June 26, 2015 at 12:04 pm


    I am formulating a serum with dry extract from algae, and the biggest problem is the color of the product. In the begining it is okay, white, slighty yellow, but with time it turns orange, brown. I tried to lower the pH and it helps a little, does anybody have other idea how to prevent brown color?
    The ingredients I used: Water,hyaluronic acid, glycerin, emulsifying wax, oil (jojoba, roseship), phenoxyethanol, extract, and then citric acid for pH.
    Thanks for the answers!
    belassi replied 8 years, 12 months ago 4 Members · 5 Replies
  • 5 Replies
  • belassi

    June 26, 2015 at 5:31 pm

    Those colour changes are usually the result of oxidation processes but I can’t say why based on that information.

  • MarkBroussard

    June 28, 2015 at 1:07 am

    Try throwing in some Tocopherol, Tocopherol Acetate or CO2 Rosemary Extract as antioxidants.  I would also switch from a dry powder algae extract to a liquid extract.  You can purchase from a number of vendors.

    Over what timeframe does it turn brown?

    Are you buying the Algae Powder Extract from a reputable source, or are you buying it from China?  I find the Chinese powder extracts always seem to be adulterated so I never use them.    
  • izzie01

    June 29, 2015 at 11:04 am

    Thank you for your answers. I was also thinking if an antioxidant would help, but because the algae itself it supposed to have antioxidant activity I thought it was not needed.

    It turns brown after 2 weeks, while I was trying to check stability on 30°C. And the dry extract that I got was from reputable company. Also, why would the liquid extract be more stable?
  • lewhitak

    June 29, 2015 at 6:05 pm

    I’ve worked with dry algae powder and the color of our finished products has been very stable. We don’t use an emulsion base, however. I would see if you can find an extract from another supplier, if possible, and see what color changes you get. Also, maybe check the species of algae that you are using as this could possibly be relevant.  

  • belassi

    June 29, 2015 at 6:51 pm

    It occurs to me that the algae may be acting as an indicator, so you should measure the starting and ending pH accurately to see if there has been a change.

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