A Comparative Study Between the Physicochemical Properties of Sesame Seed (Sesamum indicum L.) Oil Extracted by Mechanical and Traditional Pressing Methods at Khartoum State

Abstract

This study aims to make comparative between the characteristic of sesame seed oils extracted from traditional and mechanical presses. where the traditional presses produce two types of oil (normal and walad),which is collected after several days according to the interest of the press owner to maximum of seven days, this is to verily the claim of the majority of Sudanese people that the walad sesame oil is far better in quality than the other types. Samples of sesame seed taken from three traditional press were collected from Khartoum North, Khartoum and Omdurman towns to Approximate analysis, taken samples of sesame oils extracted by traditional method (camel press) (3Normal and 3Walad) to all press and one commercial sample of sesame oil which was extracted by mechanical bought from local market to physical and chemical analysis and sensory evaluation, also taken three samples from sesame cake to traditional and sesame cake to mechanical press. Approximate analysis was carried out to all mentioned samples The analysis results showed that the sesame grain used in the three traditional presses have insignificance difference in the moisture, ash and fiber, while the Khartoum press registered higher oil ratio (53.88 %) and the lower ratio in carbohydrates (13.64 %), and Khartoum North registered higher ratio in proteins (25.05 %). The oil physical properties include (Refractive index, specific density and colour), while the chemical properties include (Peroxide value, free fatty acids, saponification, iodine value, fatty acids composition and the sensory evaluation. The physical analysis revealed that there was no significant difference between different samples. While the chemical analysis shows that there was insignificant difference between the different extraction methods. The sensory evaluation there was no significant difference in the general acceptability, armoa and colour in all samples while significant difference in flavor and taste between different extraction methods. Sesame cakes samples from traditional press tested for oil content and they were revealed high quantity of oil when compared with oil content of cake obtained from mechanical press to loss oil in seed cake. The thesis concluded that the commercial sample is the most relevant to the standard and set for sesame oil through the results of the analysis. While all other samples traditionally (walad and normal) oil there was no significant difference in the two types of oil.