FREE AND ESTERIFIED MINOR COMPONENTS OF OLIVE AND Hazelnut OILS: THEIR POTENTIAL UTILISATION IN CHECKING OIL BLEND. NOTE 3

摘要

In a previous note, we described a methodology to detect hazelnut oils in blends with olive oils, based on the increasing ratio of the isomers γ/β focopherols with increased levels of hazelnut oil Additional parameters could be considered: the δ -tocopherol level detectable in hazelnut oil and present only in trace amounts in olive oil, and the sitosterol palmitate whose concentration is five time higher in the hazelnut than in the olive oil. The combination of all these parameters allows solving analytical situations, where a unique parameter was not able to detect eventual blends. Nevertheless, to further improve our methodology, we tried to evaluate the composition of the sterol fraction (total and esterified sterols), knowing that the free sterols have different composition than the esterified ones (stigmasterol is present in the free fraction △ 7-sterols are rather esterified), we evaluated the composition of both in a large number of samples of hazelnut and olive oils of different origin.