Contribution to the characterization of sterol composition of the olive oils extracted from varieties and local types compared with those issued from some introduced foreign varieties in collection at Ouazzane growing areas (northern Morocco)

The aim of the present study is the characterization and evaluation of purity parameters of oils extracted from studied varieties and local types, in comparison with those obtained from transplanted foreign varieties with to regard to elaborate sterols profiles. The β-sitosterol rates are very high (82%-87%) in Bka; BM3; BMK; BMR; BM4; M1; S1; S2; G9; G10; BLg; BRK; Dahbia; Picual; Gordal; Manzanille and Picholine of Languedoc varieties and high in BMM; M6, and Ascolana Tenera (77%-81%). For Δ5-avenasterol, BMM recorded the highest rate (14%). The Manzanille variety gave the lowest one (3.82%). The proportions of campesterol and stigmasterol are not significantly different and are relatively lower than the standard limit (4%). For cholesterol, higher rates were found in M1; Picual; BM4; BMR; Dahbia varieties, and the lowest rates were recorded in BM2; BM3; BMM; BKa; BB; S1; S2 and Gordal varieties. While the Picholine of Languedoc; BRK; G9; BLg; M6; Manzanille; A BRK scolana Tenera and BMK varieties have given intermediate levels. For the erythrodiol and uvauol, the highest proportion was found in the Manzanille and the lowest rate was found in G9. The PCA has allowed constituting three groups. The group1: Ascolana Tenera; Bka; BM2; BM3; BB; BMM; joined by Δ5-avenasterol, Δ7-stigmasterol and Δ7-avenasterol. The group2: BM4; M1; BMC; Manzanille, grouped by cholesterol, campesterol, erythrodiol and uvauol. The groupe3: S1; S2; Picual; Gordal; BLg; G10, G9; Picholine of Langudoc; BRK; Dahbia; gathered by the stigmasterol and β-Sitoserol.