Research on spent coffee grounds: from oil extraction to its potential application in cosmetics

Coffee is one of the most widely consumed beverages globally, generating significant amounts of waste, including spent coffee grounds (SCG). SCG contains valuable compounds, particularly oil, which constitutes 10–20% of its composition, depending on the plant species. This study developed an optimized method for extracting the lipid fraction efficiently, without requiring extensive time, specialized equipment, or high costs. The most effective extraction was achieved using hexane at its boiling point for 30 minutes, with an SCG-to-solvent ratio of 1:5 (m:v). Given its composition and beneficial properties, SCG oil holds potential for various industrial applications, with this research focusing on its suitability for the cosmetics industry. Notably, SCG oil demonstrated high antioxidant activity compared to commercially available coffee oils and showed no cytotoxic effects on 2D and 3D skin cell cultures. These findings highlight SCG oil as a sustainable, eco-friendly alternative to conventional cosmetic raw materials, contributing to both sustainable development and innovation in the cosmetics sector.