Tocopherol and tocotrienol content of hazelnut cultivars grown in portugal

Hazelnuts from 19 cultivars collected during 3 consecutive-year crops, in 2 different geographical localities, for a total of 79 samples, were evaluated for their contents in tocopherols and tocotrienols by normal-phase high-performance liquid chromatography coupled to a series arrangement of a diode array and a fluorescence detector. Seven compounds were identified and quantified. All samples presented alpha-, beta-, gamma-, and delta- tocopherols and beta-tocotrienol; alpha- and gamma-tocotrienols were detected in some of the studied samples. alpha-Tocopherol was the major compound in all samples, ranging from 105.9 to 226.8 mg/kg of hazelnut. Considering the generality of the obtained results, an identical qualitative and quantitative pattern was found, which can define a chemical fingerprint that may be helpful in the assessment of identity and quality of hazelnut oils. Statistical analyses were carried out in order to check for differences among cultivars, year crops, and geographical localities. Although some differences were observed when different-year crops and geographical localities were considered, neither of these factors seemed to produce considerable differences in terms of tocopherol and tocotrienol contents. Some minor differences were observed among cultivars.