Characterisation and accumulation of squalene and n-alkanes in developing Tunisian Olea europaea L. fruits

The present investigation was carried out for the analysis of hydrocarbon compounds of Tunisian Meski olives. The hydrocarbon fraction of the oils was found to contain twelve n-alkanes (C22–C36) and squalene. Results from the quantitative characterisation of the oils revealed that squalene was the most abundant hydrocarbon compound, at all development stages of Meski olive, accounting for more 92% of total hydrocarbons. Pentacosane (C25), heptacosane (C27) and tricosane (C23) represented the major compounds of n-alkanes. The highest accumulation of n-alkanes and squalene was observed at early stages of olive development [before 21st week after the flowering date (WAFD)]. The greatest decrease of these components occurred between 21st and 26th WAFD of the olives. At complete maturity of the fruit, the level of squalene and total n-alkanes was 126.52 and 9.13 mg per 100 g oil, respectively. Hence, the content of n-alkanes and squalene was remarkably influenced by the ripeness process of olive.