EFFECTS OF EXTRACTION METHODS ON PHYSICO-CHEMICAL PROPERTIES OF OIL FROM CASHEW NUTS (Anarcardium occidentale)
With a view to studying the.impact of methods of extraction on properties of oil from cashew.nuts,. two extraction 'methods were adopted to obtain oils from cashew nuts. The methods are solvent extraction using n-hexane as extractive· solvent and traditional· hydraulic press. methods.The physico-chemical properties of the extracted oil samples were analyzed and compared to each other .. Percentage oil yields .were 53.25% and 46.89% for the solvent extracted·an4 hydralic· pressrqils; respectively. The oil sample's odour· was not offensive at 'room. temperature, for either· m,ethod. Specific gravity was 0.86g/kg for solverit extracted oil and 0.94g/kg for oil obtained through hydraulic press. Saponification value ranged from 85.S.g/kg for hydraulic·press oil to 96.62 g/kgS<>r solvent extracted oil. pH values for both samples were below 7 .0, and the' refractive index forboth. samples was 1.47. The relative density value ranged from 0.9 to 0.92 at 29°C (room temperature). Both oil samples were in liquid state at room temperature and boiling points varied from 94°C-to 98°C for solvent extracted oil and hydraulic press oil respectively. The results showed thatJhe method ofextraction imposed significant changes on specific gravity, saponificatiori.value, iodi.rie value, acid value, peroxide value and relative density. However, no significant differences were recorded in parameters like free fatty acid, peroxide value and refractive index values.
Key words: Cashew nut, Solvent extraction, Hydraulic press,' Physico-chemical properties