CHEMICAL COMPOSITION AND EVALUATION OF ANTIOXIDANT PROPERTIES OF SAND BOX (HURA CREPITANS) AND YELLOW OLEANDERS (THEVETIA NERIFOLIA) SEEDS

Abstract

The sun-dried seeds of Thevetia nerifolia and Hura crepitans and the extracted oil were evaluated for proximate composition, physicochemical properties, minerals, amino acid, fatty acid and antioxidant properties using standard methods. From the results, the proximate composition (%) in T. nerifolia and H. crepitans seeds respectively were: protein (32.33 ± 0.02 and 22.36 ± 0.02), carbohydrate (3.86 ± 0.01 and 5.9 ± 0.03), moisture (3.17 ± 0.01 and 7.28 ± 0.03), fat content (60.66 ± 1.52 and 36.60 ± 0.02), crude fibre (5.23 ± 0.35 and 1.44 ± 0.01) and ash (2.47 ± 0.02 and 5.90 ± 0.01). However, the mineral composition (mg/100g) of T. nerifolia and H. crepitans seeds were sodium (149.0 and 19.35), potassium (272.5 and 48.41), magnesium (150.5 and 115.67), calcium (170.0 and 120.0), zinc (0.09 and 12 43), iron (0.07 and 26.47. The result of physicochemical properties of extracted oil of T. nerifolia and H. crepitans are; acid value (4.07 ± 0.01 and 27.09 ± 0.02) mgKOH/g, free fatty acid (2.0 ± 0.05 and 14.02 ± 0.01), saponification value ( 185.27 ± 0.05 and 248.27 ± 1.14) mgKOH/kg, iodine value (106.33 ± 2.51 and 176.96 ± 1.14) and peroxide value (6.41 ± 0.1 and 3.81 ± 0.01) meq/kg. Saturated and unsaturated fatty acid composition (%) of both T. nerifolia and H. crepitans are; saturated (26.64 and 29.27) and unsaturated (68.84 and 65.34), while the antioxidant properties in T. nerifolia and H. crepitans respectively are; total phenol (0.037 and 0.167) %, total flavonoids (0.916 and 1.285) %, reducing properties (2.201 and 1.729) mg/g, lipid peroxidation (0.827 and 1.721) mg/g and free radical scavenger activities (52.38 and 69.42) %. The study concluded that both samples are good source of protein and the extracted oil could be useful in soap and cosmetic industries as well as biodiesel production.