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Vitamin C in citrus
As we know, ordinary vitamin C (ascorbic acid) is pretty useless in cosmetic creams because it quickly oxidises and turns yellow.
However, consider this:
Citrus fruits (eg an orange) contain lots of vitamin C, in an aqueous solution, yet can remain for months on the tree and then the store, without oxidising or losing its potency.
So, what exactly does the orange have, that preserves the vitamin C? Why can’t we find out and duplicate the orange’s abilities??? -
10 Replies
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Vitamin C can remain because of the peel of fruit. The peel also contain essential oil working as preservative
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The total absence of air, I think.
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Doreen, an aqueous solution of vitamin C in a sealed container still oxidizes. Also, note that orange juice bought in a store still contains its vitamin C. There must be another mechanism. I am inclined to research the complete chemical components of orange juice.
The peel yes, contains E.O.s, but even the centre of the orange still preserves its vitamin C. -
Oranges contain other antioxidants that keep Vitamin C from oxidizing such as other vitamins (A, B complex) flavonoids and glutathione.
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Good. So what’s to stop us chemists from duplicating the orange’s antioxidants so as to be able to produce vitamin C creams that have a good shelf life without having to resort to expensive derivatives?
It occurs to me that if I could remove the sugar content from orange juice, then I could use it as the basis for a formulation. But I have no idea how to do that. -
One method I just found, would be to add yeast and ferment the juice as if making wine, which will convert the sugars into ethanol - and a small amount of methanol and higher alcohols
There are many formulae around that contain ethanol so that doesn’t worry me, but the methanol does. I don’t know if methanol is absorbed through the skin.
My trees produce over 100Kg of citrus each year, which is why this interests me so much. -
https://www.basf.com/documents/corp/en/sustainability/employees-and-society/employees/occupational-medicine/medical-guidelines/Methanol_A_BASF_medGuidelines_E021.pdf
- Answers my question. Methanol IS absorbed cutaneously. Oh BUGGER!
I have methanol in the lab. I don’t use it for anything, so I think I will get rid of it in case I have an accident with the stuff.
And I just checked - it’s only 300mg vitamin C/Kg juice, which is .03%, vanishingly small. So that is that. Useless idea. -
@Belassi I’ve been down that road long time ago, its better to use processed materials or nature identical in formulation to avoid all undesired traits such as oxidation, colour changing, unpleasant odours. On top of that, avoiding high cost of natural materials and stability issues.
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As mentioned, antioxidants are necessary, but also pH. The vitamin C is stable at slightly acidic pH. What if vitamin C is transformed in the Na salt form? As far as I know it is more stable and the pH can be around 5.5-6.
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@Belassi
Vitamin C in an orange has never been in contact with air, that was what I meant. During manufacturing of a serum, it is exposed to air, before it is packed in an airless container.
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