Lipid evaluation during the development of Pistachio seed from the region of Kairouan (Middle of Tunisia)

Pistachio seeds of "Mateur" variety, cultivated in the region of Kairouan (Middle of Tunisia), were characterized through their fatty acid (FA) composition. Both nonpolar and polar lipid (PL) classes were considered. Results showed predominance of oleic acid (C18:1) from the fifth week after pollination (WAP) in different lipid classes, and from the 11th WAP in the PLs, while linoleic acid (C18:2) predominated until the eighth WAP. FAs of PLs predominated (94.1%) until the 10th WAP, whereas those of triacylglycerols accounted for 91.1% in fully ripe seeds. In ripe seeds, the main FAs were C18:1, C16:0 and C18:2 with about 73, 12 and 10%, respectively. Amounts of total FAs (of total lipids) decreased from the 16th WAP, revealing the beginning of lipase activation in overripe seeds.