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The aim of this study was to characterize monovarietal olive oils obtained from two less known autochthonous cultivars (Bova and Buža puntoža) on the basis of sterols, triterpene dialcohols and fatty acids profile for the first time, and three monovarietal olive oils obtained from the most widespread autochthonous cultivars (Buža, Istarska bjelica and Rosinjola) grown in Istria, Croatia. β-sitosterol, Δ-5-avenasterol and campesterol were the most abundant sterols in all samples. Campesterol, β-sitosterol and Δ-5-avenasterol most significantly differentiated investigated oils. Bova oil had the highest amount of total sterols (2964 ± 458 mg/kg). Istarska bjelica oil had a peculiar sterol composition with exceptionally low β-sitosterol (67%), high Δ-5-avenasterol (27%) and the highest triterpene dialcohols percentages. Rosinjola and Istarska bjelica oils had the highest monounsaturated fatty acids level, Buža oil had the highest polyunsaturated fatty acids level, while Bova oil showed the highest level of saturated fatty acids. Tested oils obtained from the most abundant cultivars fulfilled all the demands of the current EU regulation required for virgin olive oil regarding sterols, triterpene dialcohols and fatty acids, but Bova and Buža puntoža oil slightly exceeded the upper limit for linolenic acid. Since cultivar is the source of natural variation of sterols, triterpene dialcohols and fatty acids in virgin olive oils, the knowledge about the content of these particular compounds in different monovarietal oils from autochthonous cultivars is important to determine possible disagreements with the demands of the current legislation required for virgin olive oils, in order to anticipate possible false results indicating adulteration.

Olive scale (Parlatoria oleae (Colvée)) is a common pest in Mediterranean olive orchards which primarily causes damage on olive fruits. The quality of virgin olive oil is strongly related to the health status of the olive fruits from which is extracted. In this paper the effects of olive scale (Parlatoria oleae (Colvée)) attack on the oil yield, chemical and sensorial quality, as well as on the fatty acid profile of virgin olive oil were studied. Olive fruits (Olea europea L.) from Bova cultivar (Istria, Croatia) were collected and divided into different groups according to the presence or absence of infestation by the olive scale. Olive scale attack did not induce ripening process nor stimulate oil synthesis in the infested fruits. Healthy and infested fruit groups were processed separately to produce corresponding olive oils. As regards the oil acidity, the oil samples obtained from infested fruits had similar values as samples obtained from healthy fruits. However, olive scale attack led to slight oxidative deterioration of oil, but had no effect on sensory characteristics of obtained olive oils. Fatty acid profile was slightly affected by olive scale attack: an increase of linoleic (about 13 %) and palmitoleic acid (about 8 %), but a decrease of oleic (about 3 %) and stearic acid (about 4 %) in oils obtained from infested fruits was detected. Oleic to linoleic ratio was lower in oils obtained from infested fruits indicating its lower oxidative stability.

Cilj ovog istraživanja bio je utvrditi utjecaj roka berbe maslina autohtone istarske sorte Rosinjola na udio ulja u tijestu maslina te na sastav i kvalitetu dobivenih ulja. U kasnom roku berbe utvrđena je viša vrijednost udjela ulja u suhoj tvari tijesta maslina nego u ranom roku berbe, ali je kasna berba negativno utjecala na tržišne parametre kvalitete dobivenog ulja. Udio oleinske kiseline lagano se smanjio u kasnom roku berbe, a udio linolne kiseline je porastao. Omjer oleinska/linolna kiselina, koncentracije ukupnih fenola i orto-difenola, te vrijednosti indeksa gorčine i antioksidacijski kapacitet smanjili su se u ulju dobivenom u kasnom roku berbe. Kasni rok berbe utjecao je i na opadanje koncentracije klorofila i karotenoida te vrijednosti parametara boje (a*, b* i C) u dobivenim uljima, a svjetlina ulja (L*) se povećala. U uljima iz kasnog roka berbe koncentracije većine hlapivih tvari koje utječu na pozitivna mirisna svojstva sorte Rosinjola su opale, osim aldehida kojima je koncentracija blago narasla. Senzorska ocjena ulja iz kasnog roka berbe se smanjila, kao i intenziteti svojstava maslina, jabuka, trava, gorko i pikantno u tom ulju, dok su se intenziteti svojstava slatko i ostalo zrelo voće povećali. Ulja dobivena u ranom roku berbe opisana su kao skladna i trpka s izraženim zelenim mirisnim notama, a u ulja dobivena u kasnom roku berbe kao prezrela i bez svježine. Dobiveni rezultati izuzetno su važni zbog određivanje optimalnog trenutka berbe kao i razumijevanja potencijala sorte Rosinjola za proizvodnju visoko kvalitetnih djevičanskih maslinovih ulja s ciljanim i posebnim karakteristikama.

The aim of this investigation was to determine the influence of Rosinjola cultivar fruits harvest time on oil content in olive pastes and on composition and quality of obtained oils. In the late harvest time the higher value of oil in the dry matter of olive paste was determined than in the early harvest time, but the late harvest negatively affected oil quality parameters. The proportion of oleic acid decreased slightly in the late harvest time and linoleic acid increased. The ratio of oleic/linoleic acid, total phenols and ortho-diphenols, as well as bitterness index and antioxidant capacity decreased in the oil obtained from black fruit. Late harvest time influenced the decrease in chlorophyll and carotenoid content and color parameter values (a*, b* and C) in obtained oils, but lightness (L*) increased. The concentration of volatiles responsible for positive odour of Rosinjola oils decreased, except for aldehydes which increased slightly. Sensory score of oil obtained from the late harvest time decreased, as well as intensities of sensory characteristics olive fruity, apple, green grass, bitter and pungent, while the intensities of characteristics sweet and ripe fruits increased. Oils obtained in the early harvest time were described as harmonious and astringent with pronounced green odour notes, and oils obtained in the late harvest time as overripe and without freshness. The obtained results are important for optimal harvest time determination and understanding the potential of Rosinjola cultivar for production of high quality virgin olive oil with targeted and specific characteristics.