Isolation and separation of tocopherols from olive by‐products with supercritical fluids

Supercritical fluid extraction of olive pomace, the semisolid residue obtained using two‐phase olive oil production systems, and supercritical fluid chromatographic separation of the extracts were performed to study the content of tocopherols, a group of compounds of interest for the food industry owing to their antioxidant activity. The developed method consists of supercritical CO2 extraction at pilot plant scale and subsequent fractionation by two successive depressurizations. Enrichment of α‐, β‐, and γ‐tocopherol was achieved in separator 2 when working at low densities in the first separator. Fractions obtained using high densities in separator 1 contained major proportions of triglycerides, waxes, and sterols. Tocopherols from olive by‐products were separated and quantified in an environmentally friendly way by using supercritical fluid chromatography with packed capillary columns coated with polyethylene glycol and neat CO2 according to a method previously optimized in our laboratory. The studied olive by‐products can be considered a natural source of antioxidants because substantial concentration of tocopherols have been obtained in the extracts. The isolation and separation of tocopherols from olive pomace by applying supercritical fluid technology provides an interesting approach to exploit such by‐products in an environmentally friendly way.