Dynamic accumulation of 4-desmethylsterols and phytostanols during ripening of Tunisian Meski olives (Olea europea L.)

Eleven 4-desmethylsterols and two phytostanols were identified by GC-MS during the ripening of Meski olive. The maximum levels of 4-desmethylsterols (1300 mg/100 g oil) and phytostanols (7.5 mg/100 g oil) were reached at the 26th week after the flowering date (WAFD) of fruit. P-Sitosterol (72-86% of total 4-desmethylsterols) was the major 4-desmethylsterols during the maturity of fruit, while sitostanol was the predominant phytostanols (75-85% of total phytostanols). Delta 5-Avenasterol (2-18%) and campesterol (1.6-4%) were the second and the third 4-desmethylsterol levels detected, respectively, during the ripening of Meski olive. The levels of campestanol varied from 15% to 25% of phytostanols. The rate of accumulation of those compounds occurred before 30th WAFD. Some of these compounds (4-desmethylsterols and phytostanols) showed nearly the same profile during the ripening of Meski olive which could be linked to the relation between these compounds during their biosynthetic pathway. (c) 2008 Elsevier Ltd. All rights reserved.