Analysis of olive and hazelnut oil mixtures by high-performance Liquid chromatography-atmospheric pressure chemical ionisation mass spectrometry of triacylglycerols and gas-liquid chromatography of non-saponifiable compounds(tocopherols and sterols)

We analysed the triacylglycerol, tocopherol and sterol composition of hazel nut oil, olive oil and their mixtures (90% olive oil with 10% hazelnut oil, 70% olive with 30% hazelnut oil and 50% olive oil with 50% hazelnut oil). The main triacylglycerols were 1,2,3-trioleylglycerol, 2,3-dioleyl-1-palmit oylglycerol, 2,3-dioleyl-1-linoleylglycerol and 2,3-dioleyl-1-stearoylglyce rol. Non-saponfiable compounds (tocopherols and sterols) were derivatised a s O-trimethylsilyl ethers. alpha-Tocopherol was the main vitamin E isomer i n all samples; however, small amounts of beta-tocopherol and gamma-tocopher ol were also found, beta-Sitosterol and Delta(5)-avenasterol were the princ ipal sterols in all samples; campesterol and stigmasterol were minor sterol compounds in all samples. Obtusifoliol, which was a major sterol in olive oil and oil mixtures, was not found in hazelnut oil. The discriminant analy sis showed that hazelnut oil, olive oil and oil mixtures were clearly separ ated according to their triacylglycerol composition. (C) 2000 Elsevier Scie nce B.V. All rights reserved.