Variations in the phytosterol and tocopherol compositions and the oxidative stability in seed oils from four safflower (Carthamus tinctorius L) varieties grown in north-eastern Morocco

Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four safflower (Carthamus tinctorius L) varieties originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi-arid region of eastern Morocco). Total phytosterols ranged from 3640 to 4140 mg kg -1. GC analysis allowed the identification of nine compounds, of which b-sitosterol was the major component. Total tocopherols ranged from 461.56 to 499.68 mg kg -1. HPLC analysis allowed the identification of three compounds,a-tocopherol (99.45%–98.84%), b-tocopherol (0.94%–0.5%) and c-tocopherol (0.21%–0.01%). Oxidative stability study showed that Sharda had the lowest induction period of 2.3 h compared with 7.18, 7 and 6.67 h for Cartafri, Rancho and Cartamar, respectively. Likewise, we established a positive correlation between the oxidative stability and c-tocopherol; however, this difference was not significant