Biochemical assessment of the genetic diversity among thirteen Moroccan genotypes of sesame (Sesamum indicum)

The main goal of this paper is to assess the quality of sesame seeds (Sesamum indicum L) and their oils extracted from raw seeds of 13 cultivars collected in Tadla-Azilal region of Morocco. The results indicated that the physicochemical properties studied exhibited a biochemical diversity among the 13 cultivars, with significant differences (p <0.05). Compositional analysis revealed that the sesame seeds contained considerable amounts of protein (27%) and high amounts of oil (45-55%). The characteristic of the seed oil revealed a high degree of unsaturation (79.50 -83.40% of UFA) and close values of Oleic and Linoleic acid (Oleic/ Linoleic ratio ranges between 0.80 to 0.97). Regarding quality index, there was a variation from 0.12 to 0.63 % of oleic acid for acidity, 82 to 179 mg KOHg-1 oil for saponification index, 82.9 to156.85 g of I2/100 g of oil for iodine index and 1.17 to 4.17 meq O2 kg-1 oil for peroxide value. Sesame seed oil was also found to be rich in total phenolic content (mg GAE/kg oil), chlorophyll (mg /kg oil) and carotenoid (mg/kg oil) with values ranged from 61.30 to 72.63; 0.53 to 7.57 and 0.59 to 3.34, respectively. The specific extinctions (K232) and (K270) ranged from 2.86 to 6.49 and from 0.62 to 2.13 respectively, while R-value (K232/K270) ranged from 1.66 to 8.71. These results could be beneficial and useful for sesame breeding programs in Morocco as well as in other areas of the world to develop improved cultivars with high contents of different major health-promoting compounds.