Chemical and nutritional compositions of flame of forest (Delonix regia) seeds and seed oil

Abstract

The seeds of Delonix regia were investigated for proximate, antinutrient, mineral, amino acid and vitamins compositions while the physicochemical properties, fatty acids and acylglycerols of its oil were also determined. Moisture, crude fibre, ash, crude fat, crude protein, carbohydrate, tannin, oxalate and saponin were 10.12 ± 0.59 %, 14.6 ± 0.44 %, 1.03 ± 0.02 %, 17.16 ± 0.15 %, 8.75 ± 0.04 %, 48.34 %, 1.28±0.02mg g^–1, 2.57±0.02mg g^–1, and 2.89±0.02mg g^–1, respectively. The seed contained 1604.0±0.1mg100 g^–1 Na, 1144.0 ± 0.2 mg 100 g^–1 Fe, 920.0 ± 0.6 mg 100 g^–1 Zn, 284.0 ± 0.1 mg 100 g^–1 Mn, 114.0 ± 0.1 mg 100 g^–1 Cu, 9.1 ± 0.1 mg 100 g^–1 K, 4.1 ± 0.1 mg 100 g^–1 P, 4.0 ± 0.1 mg 100 g^–1 Mg, and 1.5 ± 0.1 mg 100 g^–1 Ca. The ratios of Na/K and Ca/P were 176.26 and 0.37, respectively. Glutamic acid (147.95mg g^–1 protein) and methionine (10.87mg g^–1 protein) were the most and least abundant amino acids, respectively. The oil was liquid at room temperature, sweet-smelling, amber and had high saponification (203.40±6.72 mg KOHg^–1) and iodine (121.03±3.02 g 100 g^–1) values. The most abundant fatty acids in the oil followed the order; linoleic acid (C_18:2, 37.1 %)>palmitic acid (C_16:0, 23.90 %)>stearic acid (C_18:0, 8.20 %)>linolenic (C_18:3, 7.6 %)>oleic (C_18:1 D 9, 4.91 %)>ricinoleic acid (C_18:1, 4.50 %). The ratio of saturated to unsaturated fatty acids was 0.83. Vitamin E (33.68 mg 100 g^–1) and triacylglycerols (96.62 %) accounted for the highest contributions to vitamins and acylglycerols, respectively, in the oil. These results showed that the seeds were nutritive and good for both nutrition and industrial uses.

Keywords: Delonix regia seed, chemical composition, nutritional composition, seed oil