Extraction, Compositional and Physicochemical Characteristics of Cashew (Anarcadium occidentale) Nuts Reject Oil

Cashew nut (Anarcadium occidentale) reject is a waste material from cashew nut processing industry usually regarded as non valuable. The oil was extracted using Soxhlet and mechanical methods separately; the proximate composition and physicochemical characteristics of the oil were investigated using standard analytical methods. The mean values of various parameters for proximate composition (%) obtained were: moisture content (8.90 + 0.2), crude protein (22.10 + 0.2), crude fiber (0.90 + 0.3), ether extract (40.23 + 0.1), ash content (3.73 + 0.1), Nitrogen free extract (24.04), tannin (1.02) and phytic acid (0.50). The oil yields are 40% and 26.66% for soxhlet and mechanical methods respectively. The results of the physicochemical properties ( the mean values), for soxhlet and mechanical extraction are: Colour (Winsor orange; yellowish), Specific gravity at 200C(0.909; 0.913 ), Acid value (2.24; 2.62 + 0.4 mg KOH/g), Saponification value (212; 167 + 0.3 mg KOH/g), Iodine value (50.61; 84.77 + 0.1mgI2/g), Peroxide value (10.58; 10.0 + 0.2 Meq/kg), Free Fatty acid (2.24; 2.45 + 0.1 mg KOH/g), pH (5.7; 5.2), Density (0.91,0.90kg/m3), Acidity (114.50; 102.2 mg/l) and Turbidity (586.5; 675.2 FTU) respectively. The results showed that the method of soxhlet extraction gave the highest yield and that the cashew nuts reject oil is non- drying, non - edible and can be employed for soap making, biodiesel production and other industrial uses.