the effect of the type of extraction process and different stages of purification on the composition of sesame oil

The presence of undesirable impurities in the oil reduces the stability of the oil against oxidation, thereby decreasing the quality of the end product. this study aimed to investigate the effect of the type of oil extraction process and the different steps of purification on the amount of pahs (polycyclic aromatic hydrocarbons), lead, and arsenic and the oxidative stability of sesame oil. to do so, the cold press method was used for the control sample, and the solvent extraction method was used for the experimental samples in different purification steps (neutralization, decolorization, and deodorization). the results showed that the highest amounts of pahs were found for the sesame oil extracted by the cold press method and the lowest values of pahs were observed after deodorization. the highest concentrations of lead and arsenic were observed for the cold press-extracted sesame oil and the lowest values were found for the sesame oil after deodorization. the highest oxidative stability for the sesame oil after deodorization and the lowest oxidative stability for the sesame oil extracted by the cold press method. also, the highest peroxide value was found for the sesame oil extracted by solvent and the lowest value for the sesame oil after deodorization. the results revealed that during the solvent purification process, the amount of polycyclic aromatic hydrocarbons and heavy metals (lead and arsenic) decreased, and the oxidation stability increased compared to the oil extracted by the cold press method, and these properties improved in each step. the results of the peroxide test showed that the use of solvent for extraction caused higher oil oxidation as compared to the cold press method and the purification steps improved the oxidative stability.