Influence of cultivar and site of cultivation on levels of lipophilic and hydrophilic antioxidants in virgin olive oils (Olea Europea L.) and correlations with oxidative stability

Oxidation stability is an important property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by cultivar, year and place of production. Polyphenols, tocopherols, carotenoids, chlorophylls and fatty acids levels were correlated to oxidative stability in olive oils from three experiments: cultivar influence (18 cultivars assessed for 4 years in the same place); environmental influence by mesoclimatic (4 cultivars from 17 sites in a single region for 4 years) and macroclimate conditions (3 cultivars from 3 different regions for 3 years). Total polyphenols and saturated on polyunsaturated fatty acids ratio were shown to be the major factors in oil antioxidant stability, according to multivariate regression models. Among the surveyed cultivars, oils from 'Leccino' and from three 'local', minor cultivars ('Miniol', 'Regina' and 'Rossanello') resulted in higher oxidative stability and oils from cultivars grown in Tuscany (central Italy) showed the highest oxidative stability by comparison with northern and southern regions.