Characterization and quality assessment of mechanically and solvent extracted Niger (Guizotia abyssinica) Seed oil

Abstract

In the present study an attempt was made to evaluate physico-chemical and nutritional quality of mechanically and solvent extracted niger seed oil. SE exhibited higher yield of niger seed oil (39.34%) as compared to ME (29.23%). There was a significant variation observed in iodine value, acid value, peroxide value saponification value, free fatty acids, color and viscosity whereas, refractive index and specific gravity did not differ between niger seed oils produced by both the methods. The fatty acid profile of SE and ME oils showed marginal variation in palmitic acid. Oleic and linoleic acid showed considerable variations for both the oils. Higher total tocopherol contents were observed in ME oil (309.64 mg kg-1) as compared with SE oil (74.69 mg kg-1), respectively. Overall, it could be concluded that ME niger seed oil has superior nutritional characteristics compared with SE niger seed oil which might be attributed to the mild extraction conditions employed during mechanical extraction.