Unleashing the potential of castor oil as extraction solvent of carotenoids from tomatoes

Abstract

Adding carotenoids to cosmetic formulations aligns with the industry’s growing ethos of producing safer, more sustainable, and nature-inspired products. While synthetic compounds still have their place in cosmetics, the shift towards natural ingredients such as carotenoids reflects a more significant commitment across the industry to satisfy consumer preferences and contribute to a greener future. Castor oil is a well-known natural oil used in several cosmetic formulations because it reduces moisture loss and enhances skin hydration. However, it’s only added to cosmetics simultaneously with all the other components, including natural extracts. Thus, this work goes behind literature and classic downstream approaches. A simplification of cosmetics formulations is intended by using castor oil directly as the extraction solvent of natural bioactive compounds, such as carotenoids from tomatoes. A comparison of its extraction performance with conventional extraction solvents was made, and all the process operating conditions were optimized (SLR = 0.06 gbiomass.mLsolvent-1, percentage of castor oil = 50 % (v/v), and time of extraction = 90 min) to achieve a maximum recovery of 3.2 ± 0.2 mgCar.gbiomass-1. Additionally, its capacity as a preservative of carotenoids degradation was also tested against a conventional solvent to enhance natural pigments’ shelf life showcasing increased stability (especially at 75 °C), a current problem of their application in industry. The environmental performance of the process proposed was analyzed based on the carbon footprint, with electricity consumption identified as the most significant contributor. This impact could be greatly reduced by utilizing photovoltaic energy. Lastly, a conceptual process design has been proposed to envision its practical application in an industrial setting.