Bio-based Algae Oil: an oxidation and structural analysis.

Abstract

In search of natural components, vegetal oils are increasingly becoming more popular in cosmetics. However, high oxidation instability, presence of potential allergens and synthetic anti-oxidants have limited their applications so far. Therefore, a need exists for a natural emollient with high oxidation stability. In this work, we report on a novel sustainably produced triglyceride containing primarily three monounsaturated oleic acid chains, dubbed 'Bio-Based Algae Oil' hereafter, as a natural emollient for cosmetic formulations. To produce Bio-Based Algae Oil, simple sugars are converted into triglyceride oils using microalgae fermentation with minimal environmental impact. Bio-Based Algae Oil was compared to other commonly used triglyceride-based emollients in the skincare industry in terms of thermal/oxidation stability, composition and moisturizing properties. Oxidation stability of emollients was compared using Rancimat and pressurized differential scanning calorimetry (PDSC) techniques. Fatty acid composition of each oil was analysed using proton nuclear magnetic resonance (1 H-NMR) and gas chromatography (GC) techniques to correlate unsaturation level of each oil to its oxidation stability. We also conducted an in vivo moisturizing study in which skin hydration level of human subjects was compared before and after application of emollient up to 24h. Results showed that Bio-Based Algae Oil was the most stable emollient in thermal and oxidation stability studies given its low unsaturation and high anti-oxidant content determined by 1 H-NMR and GC techniques. It also provided the highest skin hydration level when applied on skin demonstrating its efficacy as a moisturizing emollient in cosmetic formulations. Compositional analysis of Bio-Based Algae revealed that it is a triglyceride containing primarily three monounsaturated oleic acid chains with very low polyunsaturated fatty acid content resulting in high oxidation stability and consequently prolonged shelf-life. Given its sustainability, high oxidation stability and skin health benefits such as moisturization demonstrated during an in vivo study, we envision to utilize Bio-Based Algae Oil in many cosmetic formulations across skincare, suncare and bath and shower markets.