Concentration of stigmasterol, β-sitosterol and squalene from passion fruit (Passiflora edulis Sims.) by-products by supercritical CO2 adsorption in zeolite 13-X

Phytosterols and squalene, widely applied in pharmaceutical and food industries, were extracted and concentrated from passion fruit by-products (PFBP). A supercritical extraction using CO2 (SFE) was performed for PFBP, and the obtained extract underwent supercritical fractionation (SFA) (inlet at 35MPa, 50-70 ℃) in a column packed with zeolite 13-X (5-15g). The extraction and fractionation yields were measured, whereas the composition of the PFBP extract and their fractions was assessed by gas chromatography-mass spectrometry (GC-MS). Fractionated extract recovered presented different trends depending on temperature and zeolite mass combinations, and the highest recovery (approximately 95%) was achieved at 50 ºC with 15g of adsorbent. At the same SFA conditions, the concentration of squalene, β-sitosterol and stigmasterol was twice that obtained in PFBP extract. Finally, SFA proved to be a clean and effective technique to concentrate squalene and phytosterols from PFBP, which should be extended to other food residues.