Cold and hot hexane extraction of oil from olive pulp and seeds of Leccino cultivar

U ovom radu istražena je učinkovitost hladne i tople (Soxhlet) ekstrakcije ulja iz suhe tvari liofiliziranih maslinovih tijesta (bez koštice i s košticom) te iz sjemenki ploda masline sorte Leccino. Istražen je i utjecaj ekstrakcije na sadržaj ukupnih fenolnih tvari i orto-difenola u dobivenim uljima. U maslinovim tijestima i sjemenkama određen je udio ukupnih fenola i antioksidacijski kapacitet (IC50). Hladna i topla ekstrakcija pokazale su se podjednako učinkovite u izdvajanju ulja iz liofiliziranih maslinovih tijesta, dok je topla ekstrakcija bila učinkovitija u izdvajanju ulja iz sjemenki. Maslinova tijesta bez koštice imala su najveći udio fenolnih tvari (12,9 mg g-1 s.t.) od tri ispitivana biljna materijala. Stoga su i ulja dobivena iz njih, osobito ona dobivena toplom ekstrakcijom, sadržavala najveće udjele ukupnih fenola (396,7 mg kg-1) i orto-difenola (206,3 mg kg-1). U odnosu na maslinova tijesta, sjemenke su imale statistički značajno niži udio ukupnih fenola te višestruko niži antioksidacijski kapacitet. Rezultati su potvrdili da se uklanjanjem koštice smanjuje negativni utjecaj peroksidaza iz sjemenki na fenolne tvari u tijestu i ulju, te upućuju da se primjenom tople ekstrakcije povećava topljivost fenolnih tvari iz biljnog materijala u ulju.In this work, the effectiveness of cold and hot (Soxhlet) extraction of oil from the dry matter of lyophilized olive pastes (without pit and with pit) and seeds of olive fruits of Leccino cultivar, was investigated. The effect of extraction on the content of total phenols and ortho-diphenols in the obtained oils was also investigated. Total phenols content and antioxidant capacity (IC50) were determined in olive pastes and seeds. Cold and hot extraction proved to be equally effective in extracting oil from lyophilized olive pastes, while hot extraction was more efficient in extracting oil from seeds. Olive pastes without pits had the highest total phenols content (12.9 mg g-1 of dry mass) of the three investigated plant materials. Therefore, the oils obtained from them, particularly those obtained by Soxhlet extraction, contained the highest total phenols content (396.7 mg kg-1) and ortho-diphenols (206.3 mg kg-1). Compared to olive pastes, the seeds had a statistically significantly lower total phenols content and a multiple lower antioxidant capacity. The results confirmed that pits removal reduces the negative influence of peroxidases from seeds on the phenol compounds in the olive paste and in the oil, also suggesting that hot extraction increases the solubility of phenols from plant material in the oil