Comparative profiling of volatile compounds and fatty acids in pomegranate seed oil. Soxhlet vs. CO2/IPA extraction for quality and circular bioeconomy goals

This study compares the chemical profiles of pomegranate seed oil (PSO) from two cultivars, Granato (G) and Roce (R), extracted by Soxhlet and supercritical CO2/isopropanol. GC-MS and NMR analyses confirmed punicic acid as the dominant fatty acid, with alpha-eleostearic, oleic, and linoleic acids in lower amounts. Supercritical extraction increased yield (about 18%) and selectively raised alpha-eleostearic and linoleic acids. Volatile organic compound (VOC) profiling by HS-SPME-GC-MS showed higher aldehydes, esters, and terpenes in supercritical extracts, including (E)-cinnamaldehyde (absent in Soxhlet). Soxhlet oils contained more hydrocarbons, suggesting thermal degradation. Overall, supercritical CO2/IPA proved more sustainable and selective, preserving nutritional and aromatic quality and supporting PSO's potential in food, nutraceutical, and cosmetic uses.