New vitamin E isomers (gamma-tocomonoenol and alpha-tocomonoenol) in seeds, roasted seeds and roasted seed oil from the Slovenian pumpkin variety 'Slovenska golica'

Bojan Butinar; Milena Bučar-Miklavčič; Carlo Mariani; Peter Raspor

doi:10.1016/j.foodchem.2011.03.072

New vitamin E isomers (gamma-tocomonoenol and alpha-tocomonoenol) in seeds, roasted seeds and roasted seed oil from the Slovenian pumpkin variety 'Slovenska golica'

Food Chem. 2011 Sep 15;128(2):505-12. doi: 10.1016/j.foodchem.2011.03.072. Epub 2011 Mar 21.

Authors

Bojan Butinar¹, Milena Bučar-Miklavčič², Carlo Mariani³, Peter Raspor⁴

Affiliations

¹ Laboratory for Olive Oil Testing, Science and Research Centre of Koper, University of Primorska, Zelena ulica 8, SI-6310 Izola, Slovenia.
² Laboratory for Olive Oil Testing, Science and Research Centre of Koper, University of Primorska, Zelena ulica 8, SI-6310 Izola, Slovenia; LABS, LLC - Institute for Ecology, Olive Oil and Control, Zelena ulica 8, SI-6310 Izola, Slovenia.
³ Stazione Sperimentale per le Industrie degli Oli e dei Grassi, Via Giuseppe Colombo 79, 20133 Milano, Italy.
⁴ Food Science and Technology Department, Chair of Biotechnology, Microbiology and Food Safety, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000, Ljubljana, Slovenia. Electronic address: peter.raspor@bf.uni-lj.si.

PMID: 25212163
DOI: 10.1016/j.foodchem.2011.03.072

Abstract

The Štajerska region in north-eastern Slovenia and the Styria region in southern Austria have a long tradition of growing pumpkins (Cucurbita pepo L.) as an oil crop. GC-MS determination of the free and esterified minor compounds in oil of roasted pumpkin seeds from the Slovenian C. pepo L. variety 'Slovenska golica' revealed the presence of two previously unreported compounds: alpha-tocomonoenol and gamma-tocomonoenol. Using the GC-MS data, reference samples (Crude Palm Oil) and tocopherol and tocotrienol standards it was possible to assign and quantify alpha-tocomonoenol (17.6±0.6μg/g) and gamma-tocomonoenol (118.7±1.0μg/g) compounds in roasted 'S. golica' seed oil using HPLC. The concentrations of alpha-tocopherol and gamma-tocopherol were 77.9±1.9μg/g and 586.0±4.6μg/g, respectively. Surprisingly the gamma-tocotrienol concentration found was only 6.9±0.2μg/g. Analysis of the seeds from which the oil was pressed showed the initial gamma-tocotrienol amount was even lower (1.6±0.1 and 2.2±0.1μg/g in the ground and roasted seeds, respectively) than in the roasted seed oil.

Keywords: Alpha-tocomonoenol; Cucurbita pepo L.; GC-MS; Gamma-tocomonoenol; HPLC; Pumpkin seed oil; Vitamin E.