PHYSICOCHEMICAL PROPERTIES AND STORAGE STABILITY OF CRUDE PALM KERNEL OIL TREATED WITH THE EXTRACTS AND GRITS OF SELECTED NIGERIAN SPICES

The objective of this study was to evaluate the storage stability of crude palm kernel treated with the grits and n-hexane extracts of Aframomum danielli (A. danielli), Monodora myristica (M. myristica) and Monodora tenuifolia (M. tenuifolia) and stored for 24 weeks at room temperature. Untreated palm kernel oil and α-tocopherol were used as controls. Storage stability indices were: free fatty acid and peroxide value. The order of free fatty acid development from lowest to highest was A. danielli extract < A. danielli grits < α -tocopherol (Vitamin E) < M. myristica extract < M. tenuifolia extract < M. tenuifolia grits < M. myristica grits< untreated sample. Again, the order of peroxide value development from lowest to highest was α-tocopherol (5.63meq/kg) < A. danielli extract (6.04meq/kg) < M. myristica extract (6.66 meq/kg) M. tenuifolia extract (9.09 meq/kg) < A. danielli grits (9.33meq/kg) < M. tenuifolia grits (10.10 meq/kg) <M. myristica grits (10.28 meq/kg)< untreated sample (13.54meq/kg). The spice extracts had better storage stability than their grits. The study suggests that the n-hexane extracts and grits of A. danielli, M. myristica and M. tenuifolia can be used to extend the shelf life of palm kernel oil.