-
How can I extend the shelf life of a lotion containing sunflower oil?
I live in India, and all sunflower oil commonly sold here has a shelf life of 6-8 months. Cooking oil often contains antioxidants like Vit E or TBHQ or citric acid depending upon the brand. Does this mean that a lotion containing these sunflower oils can’t be used beyond those 6-8 months, or can I use a combination of stable oils, preservatives, antioxidants or chelators to make the lotion last at least 1 year at average room temperature of 30 Celsius?
Additional info: I use sunflower oil for most of the oil phase in emulsions, at roughly 15-20 percent of total weight. I also use other oils or butters, including the much-reviled light liquid paraffin and 0.1 % Vit E as antioxidant, and I wonder if the paraffin would help stabilize the formula against oxidation.
-
4 Replies
-
I am sure that the food industry follows the cosmetic industry in regard to ‘tricks of the trade’. In cosmetics it is often the case that Vit E is added (adulterated) to oils that have sat in the system longer than was initially intended. Hence sometimes by the time it gets to the end user… adding any additional Vit E is already in the realm of pro-oxidant vs the desired realm of antioxidant.
Hence, when I preserve oils that don’t originally source from ICSC out of Denmark, I focus more on ROE (Rosemary Oil Extract…. Not rosemary EO!), Ascorbyl palmitate, and one final option (that I don’t use) is sodium phytate. Since oils sourced from ICSC have unlikely (assuming no middleman) been adulterated with MT-E …. one can safely add a small amount of MT-E and still get the good from it.
Mixing more stable oils…. do not enhance the stability of the less stable oils…. it simply reduces their inclusion rate… (not a bad concept).
Oxidation…. can be visualized by a snowball rolling down (yeah, I see the irony of this illustration to someone from India) a hill. It starts small and increases in mass and speed. Oxidation is the same! Hence starting with the freshest oils…and treating them the moment you receive them (vs when you use them in formula) are all proactive steps you can take. Buy the smaller quantities, so you use them faster and replace them sooner. Last, but surely the most important….store your oils in the refrigerator.
Good Luck.
-
Thanks, these are good ideas!
On the pro-oxidant thing though…https://youtu.be/ioucAvsnziw?si=eJYD7TzqJgx4wU3I is a video where Belinda Carli from the Institute of Personal Care demonstrates that it takes a full 2% Vit E to demonstrate prro oxidation effects. So if I add 0.2% on top of another 0.2%, that should be safe, right? Then again that’s another discussion altogether…and redundant for a DIYer with a Vit E skin allergy issue.
-
<div>If you have access to high-oleic sunflower oil, using that instead of the regular type will make a huge improvement in shelf life. </div>
You’ll still want to use antioxidants etc., but the big reduction in short lived fatty acids (Linolenic, linoleic) vs oleic should easily double or treble shelf life.
-
Unfortunately, the high linolenic and linoleic acids are what I need, since they are good moisturizers for acne prone skin. I’m acne prone myself, and live in a HOT humid climate…so I look for non-comedogenic, cost effective options wherever possible.
-
Log in to reply.