Studies on Mango (Mangifera indica, L.) Kernel Fat of Some Kenyan Varieties in Meru

Abstract

Four varieties (Boribo, Dodo, Kagege, and Kent) of ripe mango (Mangifera indica, L.) fruits were collected directly from the farmers in Meru County (Kenya), peeled, depulped and the stones deshelled. The mango kernels obtained were crushed, sun-dried, and extracted using petroleum ether (b.p. 40–60 °C). The fat content of the mango kernels varied from 8.5 to 10.4 % depending on the variety. The mango seed kernels constituted about (4.76–6.70 %) crude protein (Nx6.25), (1.74–2.26 %) crude ash, (71.90–76.28 %) crude carbohydrate, (1743–1782 kJ) gross energy, (1547–1576 kJ) available energy, and mean protein:energy ratios of (2.63–3.76 mg/kJ) all on a moisture free basis. The moisture content of fresh mango seed kernels varied from 42.1 to 67.6 % depending on the variety. The fat had a melting point of 25–33 °C, an iodine value of 51.08–56.79, an acid value of 4.49–7.48, free fatty acid (as oleic) of 2.26–3.76, a saponification number of 188.8–195.9, unsaponifiable matter of 2.26–2.74 %, a peroxide value of 0.40–0.75, a refractive index(40 °C) of 1.4562–1.4597 and a specific gravity of 0.9017–0.9087. Investigation of the fatty acid composition revealed(GLC) nine fatty acids: tetradecanoic acid (trace-0.05 %), pentadecanoic acid (trace– 0.09 %), hexadecanoic acid (4.87–10.57 %), heptadecanoic acid (trace-O.10 %), octadecanoic acid (24.22–32.80 %), 9-(Z)-octadecenoic acid (46.37–58.59 %), 9-(Z), 12-(Z)- octadecadienoic acid (6.73–10.35 %), 9-(Z), 12-(Z), 15-(Z)- octadecatrienoic acid (0.601–1.8 %), and eicosanoic acid (0.62–1.64 %). The fat had the typical characteristics of a vegetable butter.