Recovering value from organic waste materials: Supercritical fluid extraction of oil from industrial grape seeds

Supercritical extraction of oil from grape seed samples obtained from a Portuguese industry was carried out at temperatures from (313-333) K, pressures up to 40.0 MPa and different scCO(2) flow rates. The qualitative analysis of the crude oil was carried out by NMR. The fatty acids were analyzed by GC-Fid with reference to the parameters in Annex I to European Commission Regulation. The results show similar content of TAGs and DAGs both in the n-hexane and scCO(2) extraction methods, but the latter have higher PUPA and lower saturated fatty acids content. A dynamic model was used to simulate the extraction curves in gPROMS ModelBuilder. The grape seed oil was represented as either a one or a three component mixture of triacylglycerols, and the deviation between the experimental and calculated extraction yields was in the range (2-9) % for the first, and (4-11) % for the second case.