title: Variability of 4-Monomethylsterols and 4,4'-Dimethylsterols in Olive Oil and Their Use as Indicators of Olive Variety, Ripening Degree, and Oil Storage Temperature.
abstract: To investigate the variability of 4-monomethylsterols and 4,4'-dimethylsterols in olive oil as a result of variety, ripening, and storage temperature, 36 samples were subjected to gas chromatography with flame ionization detection (GC-FID) and with mass spectrometric detection (GC-MS), and results were processed by univariate and multivariate statistics. Relative amounts (percent) of β-amyrin, cycloartenol, and 24-methylenecycloartanol accounted for the most variation due to variety, while citrostadienol (percent) and 24-methylenecycloartanol (milligrams per 100 g) were strongly affected by ripening. Multivariate statistics differentiated olive oils regardless of storage conditions, which implied the possibility to use 4-monomethyl- and 4,4'-dimethylsterols as indicators of variety and ripening degree for fresh and stored oils. Absolute changes in 4-monomethyl- and 4,4'-dimethylsterols after storage were of a much smaller magnitude, meaning the investigated olive oils essentially retained health-beneficial features that derive from these compounds. Relative changes caused by storage were specific for each storage temperature and were useful in discriminating oils by linear discriminant analysis.
authors.affiliation: †Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Lukić
authors.affiliation: †Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia.
authors.forename: Igor
authors.initials: I
authors.lastname: Lukić
authors.affiliation: †Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sladonja
authors.affiliation: ‡Faculty of Food Technology, Josip Juraj Strossmayer University of Osijek, Franje Kuhača 20, 31000 Osijek, Croatia.
authors.forename: Vlasta
authors.initials: V
authors.lastname: Piližota
mesh_terms: D061353:Food Storage; D005638:Fruit / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D031658:Olea / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D000069463:Olive Oil / Q000737:chemistry*; D010840:Phytosterols / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D000069463:Olive Oil; D010840:Phytosterols
keywords: 4,4′-dimethylsterols; 4-monomethylsterols; Olea europaea L.; multivariate statistical analysis; olive oil; ripening degree; storage; variety