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

摘要

Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four saf-flower (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 P-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, α-tocopherol (99.45％-98.84％), β-tocopherol (0.94％-0.5％) and γ-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 γ-tocopherol; however, this difference was not significant.