Separation, identification and quantification of the unsaponifiables of cottonseed oil and its deodorizer distillate

Abstract

This study was conducted to separate, identify and quantify the unsaponifiables of cottonseed oil and its deodorizer distillate. The AOCS extraction method was used to separate the unsaponifiables from refined, bleached and deodorized (RBD) cottonseed oil and its deodorizer distillate. A silylation method was then used to identify and quantify the tocopherols and sterols which are the major components of the unsaponifiable materials of RBD cottonseed oil and its deodorizer distillate. Quantification of unsaponifiables was conducted using gas chromatography. The percentage of total unsaponifiables was found to be 2% in RBD cottonseed oil and 53.9% in the deodorizer distillate. The total tocopherols in RBD cottonseed oil were 3.6% of the total unsaponifiables (which included 2.3% α tocopherol and 1.37% β+γ tocopherol) and total sterols were 31.4% of total unsaponifiables (which included 1.8% stigmasterol, 2.3% campesterol and 27.2% β sitosterol). In the distillate, total tocopherols were 12.64% of the total unsaponifiables (which included 4.4% α tocopherol, 8.2 % β+γ tocopherols) and total sterols were 65.1% of total unsaponifiables (which included 1.2% stigmasterol, 6.6% campesterol and 57.3% β sitosterol).