Spent coffee ground oil as a valuable source of epoxides and epoxidation derivatives: Quantitation and characterization using low-field NMR

Coffee waste, commonly referred to as spent coffee grounds (SCG), is currently discarded and has a negative impact on the environment. However, SCG are rich in valuable ingredients including 15-20% oil, which has a profile comparable to the vegetable oils used in the production of epoxides, biobased polyols, and polymers. Our first objective was to evaluate the efficiency of three different methods, namely Soxhlet, pressurized fluid extraction, and supercritical CO2 (scCO2) on SCG oil extraction. Additionally, we aimed to test the potential of low-field (LF) NMR to analyze SCG oil and monitor the formation of epoxides and biobased polyols. Finally, we evaluated epoxidized SCG oil as a plasticizer for improving the properties of poly(3-hydroxybutyrate-co-3hydroxyvalerate) (PHBV) bioplastic. Overall, SCG showed a promising potential as a source of biopolymer precursors, while LF NMR can be an efficient and economic tool for oil evaluation and reaction monitoring.

Automated summary

Coffee waste, or spent coffee grounds (SCG), is rich in valuable ingredients and shows potential as a source of biopolymer precursors. Low-field (LF) NMR can be an efficient and cost-effective tool for oil evaluation and reaction monitoring.