Effect of Heavy Metals on Qualities of Solvent Extracted and Mechanical Extracted Oils

Abstract

This work was carried out to determine heavy metals contamination levels and comparison between vegetable oils extracted by solvent and mechanical press. Groundnut oil (solvent) contain high level for lead(Pb) 0.9 ppm and compressed oil .02ppm,sesame oil (solvent, compressed) was found in standard limit(0.1ppm).The copper(Cu) content in sesame oil (solvent, compressed) was found in standard (0.1ppm),in groundnut oil (solvent, compressed) 0.064,0.138ppm respectively.Iron(Fe) content in sesame oil(solvent, compressed) 0.2,0.157ppm respectively and standard 0.1ppm,groundnut oil (solvent, compressed) 0.158,0.131ppm respectively. Peroxide value increased in groundnut oil (solvent) 12.6meq/kg, groundnut oil (compressed, manufacture) 4, 9.33meq/kg respectively, the sesame oil (solvent, compressed) 9.66,3.33 meq/kg. Acid value increased in sesame oil (solvent) 1.066 mgKOH/g, groundnut oil (manufacture ,solvent,compressed)1.514,0.505,0.309mgKOH/g respectively, sesame oil (compressed) 0.336mg KOH/g .Iodine value was increased in all sample groundnut oil (solvent, compressed, manufacture) 260.18,213.63,158.65 mg iodine/100g fat respectively, sesame oil (compressed, solvent) had the same value 225.28 mg iodine/100g fat. High value of saponification in groundnut oil (manufacture) 200.0 mg/g, sesame oil (compressed, solvent) 185.97,172.34mg/g, groundnut oil (compressed, solvent)178.42, 163.08 mg/g respectively. The specific gravity of groundnut oil (compressed, solvent) had the same value 0.909, sesame oil (compressed, solvent) 0.911, groundnut oil (manufacture) 0.911.The refractive index in sesame oil (compressed, solvent) 1.4755, groundnut oil (compressed, solvent, manufacture) 1.4735.