Optimum extraction technology for the seed oil of Nigella sativa L.

Abstract

Seed oil of Nigella sativa L. is a popular edible oil in Egypt. How to improve the extraction efficiency of the oil will expand the use of the resource. In this paper, the four extraction factors, particle size of the seed, liquid-seed ratio, extraction time, and temperature, were optimized by the single-factor and orthogonal experiment to increase the extraction yield and linoleic acid concentration. The results showed that the twice extraction technology could increase the oil rate of 23.55% compared with the once extraction technology. The extraction rate of the once extraction could reach 33.51% under the conditions of liquid-seed ratio: 9: 1 mL/g, extraction temperature: 35°C, extraction time: 1 h, and particle size: 60 meshes. The optimum twice extraction conditions with the extraction rate of 43.78% were 8: 1 ml/g, 40°C, 1.5 h, and 60 meshes. Besides, the highest concentration of linoleic acid (58.09 mg/g) was twice extraction condition with 7: 1 mL/g, 40°C, 2 h, and 60 meshes.