Supercritical CO2 extraction and solvent-free rapid alternative bioepoxy production from spent hens.

• Spent hens are by-product of poultry and potential feed stock of lipids. • Lipids extracted using supercritical CO 2 and parameters investigated. • Extracted lipids epoxidized in solvent free conditions. Spent hens are by-product of egg and hatching egg production and a potential source of renewable compounds. In this study, lipids were extracted using supercritical carbon dioxide (SC−CO 2) at 50 − 70 °C, 30 − 50 MPa, and constant CO 2 flow rate of 1 L/min. The maximum yield of total lipid 37 ± 0.4 % (w/w) with 91.4% recovery was obtained at 50 MPa/70 °C. Fatty acid compositional analysis was performed using gas chromatography with flame ionization detector (GC-FID). Helium ion microscopy (HIM) was used to assess the morphological changes before and after extraction. Furthermore, epoxidation of the extracted lipids was conducted with and without the use of a solvent, where the solvent-free epoxidation was completed within 20 min and the yield was comparable. The reaction progress was monitored by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and proton nuclear magnetic resonance (¹H NMR) spectroscopy analysis, which showed the conversion rates of 59.8, 84.2 and 100% at 5, 10, and 20 min, respectively. The findings suggest that an alternative bio-epoxy can be produced using SC−CO 2 extraction and solvent-free oxidation of extracted lipids from poultry industry waste/by-product. [ABSTRACT FROM AUTHOR]