Physicochemical Characterization of Samples of Vegetable Oils Traded in Local Markets

Abstract

In this study, several physical and chemical properties were estimated (density, viscosity, moisture content, acidity, saponification number, and ester number) for various vegetable oil samples available in the Libyan local market. The results indicated no differences in the density and viscosity values of the corn oil samples, although differences were observed among the sunflower oil samples. Regarding moisture content, the highest value was found in corn oil (Al-Safwa) at 8.2%, while the lowest was in corn oil (Alhadayiq) at 30.18%. As for the chemical properties assessed, the acidity and saponification values of all samples did not meet standard specifications; the standard acidity is 0.6 mg/g, and the standard saponification number ranges from 187 to 194 mg/g. The acidity values varied from 2.805 mg/g for corn oil (Alhadayiq) to 3.703 mg/g for sunflower oil. The saponification number was lowest in the sunflower oil sample at 31.76 mg/g and highest in the corn oil sample at 68.80 mg/g. Additionally, the ester number values were also out of specification, with the lowest value for sunflower oil (Alzuhra) at 28.22 mg/g and the highest value for corn oil (Almarwa) at 65.83 mg/g.