When you're using fruit extracts - and, indeed, most extracts - you'll be adding them to the cool down phase at around 0.5%. For something like a shampoo, lotion, or other thick product, I like to pour a little heated water at 45˚C to 50˚C (the temperature of our cool down phase) - not much, maybe 5 to 10 ml - into the powdered extract and mix until it dissolves. Then I add it to the product and mix well. If I'm adding it to something like a mister or toner - something that's pretty much all water - I don't bother dissolving it!
Here's a blast from the past (March 10, 2010) with a post on strawberries!
This extract is recommended for oily skin to help with sebum production and large pores. It is an astringent powder, thanks to the hydroxybenzoic acid gallic acid, a great wound and burn healer as well as an astringent. Chlorogenic acid is recommended for acne prone skin as it offers anti-bacterial, anti-inflammatory, and anti-oxidizing properties.
The phytosterol kaempferol offers amazing anti-oxidizing and free radical scavenging properties, as well as anti-inflammatory help for reddened skin, an increase in skin's barrier protection abilities, a reduction in transepidermal water loss (TEWL), a reduction in itching and dry skin, and help improving the quality of weather damaged skin.
Strawberry extract contains Vitamin C, a great anti-oxidizing and chelating ingredient.
One of the main features of strawberry extract is the ellagic acid, which you might remember from pomegranate and borage oil and mango butter. It is being used as a post-sun exposure ingredient to prevent freckling and spots that might arise after UV exposure. It appears ellagic acid is a tyrosine inhibitor (tyrosine plays a role in melanin synthesis or melanogenesis). It can also reduce the destruction of collagen and act as an anti-inflammatory. One bonus is ellagic acid can help regenerate skin cells, which may lead to thickened skin, which can help reduce the look of aging.
Strawberries contain anthocyanidins and anthocyanins (not to be confused with proanthocyanidins and procyanadins from green tea extract), which are water soluble flavonoids that give colour and protection to plants. (They are anthocyanins when they contain a glucose molecule, anthocyanidins when they don't.) They are very good anti-oxidants, scavenging those free radicals that lead to rancidity and spoilage. The colour is dependent upon pH - when the solution is below ph 3 (very acidic), the colour is red. At neutral pH (7), they show violet, and above pH 11 (very basic) they show blue. (They can be used to determine pH level at home!) Strawberries contain between 15 to 20 mg of anthocyanidins and anthocyanins in 100 grams of fruit.
So what does this all mean for us when we use strawberry extract? We can use it at up to 0.5% in water containing creations when we dissolve it in warm water and add it to the cool down phase for some great anti-oxidant, astringent, and anti-bacterial features. A huge down side for strawberry extract - it is really hard to preserve.
preservatives together to keep it nicer longer (for instance 1% Germaben II and 0.5% Germall Plus) but it is an extract that doesn't play well with water. And don't even think about using it in a clay mask unless you make it every single time! Clay is a great breeding ground for ick, and combined with strawberry extract it will go bad very very quickly no matter how well you preserve it.
Is it worth it given all these problems? I say, yes! Strawberry extract not only has great label appeal - everyone loves strawberries! - but it's a great inclusion in facial cleansers or toners meant for oily, large pored, or acne prone skin. It's probably not the best ingredient for newbies who are unsure about their ability to preserve, but if you're a confident formulator, you can work with strawberry powder in your products. I personally wouldn't use it in a lotion as there are too many things that can go wrong. Stick to toners, sprays, cleansers, and surfactant mixtures with strawberry extract. Or consider using it in a gel toner just for a change from the liquid stuff!
Are you working with strawberry extract? What do you find works for you? Share your thoughts!
Join me tomorrow for more fun formulating with fruit extracts!