Vortex fluidic device-driven production of medium-chain free fatty acids for organic cosmetic ingredients

Abstract

Medium-chain free fatty acids (MCFFA), such as capric acid and caprylic acid, are valuable ingredients in organic cosmetics and are well-known for their antibacterial properties. To produce such MCFFA, conventional triglyceride saponification methods are commonly employed; however, these methods are often inefficient, energy-intensive, and fail to meet sustainable MCFFA production standards. This study utilises a Vortex Fluidic Device (VFD), a thin-film processing technology, to enhance the production efficiency and the yield of MCFFA from Palmester oil, composed of 40% capric acid (C10) and 60% caprylic acid (C8). Operating at 5000 rpm in continuous flow mode at 70 °C, the VFD achieved a 95% yield of MCFFA with 96% purity, representing a 1.44-fold increase in yield compared to the conventional water-bathing method under the same processing conditions. In contrast, the benchtop methods yielded 37% fatty acid ethyl esters as byproducts with significantly lower purity. Rheological analysis revealed that the MCFFA produced via VFD, resulting from the ethanol used in the saponification process, exhibited low viscosity. DSC analysis confirmed the thermal stability of the product, underscoring its potential in industrial applications. Moreover, MCFFA showed superior antibacterial activity, producing larger inhibition zones compared to commercial capric acid and caprylic acid at the same concentrations. These findings highlight the potential of VFD as a novel technology for producing high-purity MCFFA with enhanced antibacterial efficacy, supporting its application in organic cosmetic formulations.