Abstract
Application of novel technologies such as microwave and pulsed electric fields (PEF) might increase the speed and efficiency of oil extraction. In the present research, PEF (3.25 kV/cm electric field intensity and 30 pulse number) and microwave (540 W for 180 s) pretreatments were used to study the process of oil extraction from black cumin (Nigella sativa) seeds. After applying the selected pretreatments, the oil of seeds was extracted with the use of a screw press and the extraction efficiency, refractive index, oil density, color index, oxidative stability, and chemical components of oil and protein of meal were evaluated. The achieved results expressed that PEF and microwave pretreatments increased the oil extraction efficiency and its oxidative stability. Different pretreatments didn't have any significant influence on the refractive index of black cumin seed oil (p>.05). When microwave and PEF were used, the oil density showed an enhancement as the following: 1.51% and 0.96%, respectively in comparison with the samples with no pretreatments. Evaluation of the extracted oils, using GC/MS analysis indicated that thymoquinone was the dominant phenolic component in the black cumin oil. Finally, the SEM analysis revealed that microwave and PEF can be useful in the extraction of oil from black cumin seeds since these treatments damaged cell walls and facilitated the oil extraction process.
Highlights
Oils and fats are important nutrients in the case of health and in business
Comparison of data means, using Duncan’s test indicated that use of pulsed electric fields (PEF) and microwave pretreatments in this research led to an increase in the efficiency of oil extraction process (Figure 1)
It was specified that those samples pretreated by microwave had a higher oil extraction efficiency in comparison with other samples
Summary
Oils and fats are important nutrients in the case of health and in business. Due to these reasons, much research and investment are allocated to study them. Oils and fats are responsible to supply a significant part of required energy for body, necessary fatty acids, and fat-soluble vitamins (Kebriti, HoseiniMazhari, Gerami, Ghiassi, & Esfandyari, 2011). With the growth and increase in general knowledge, the demand for health-promoting oils in addition to energy supply increased. Oils and fats are prepared from various plant and animal sources of which have different metabolic, physical and chemical properties (Zomorrodi, Shokrani, Shahedi, & Dokhani, 2003). Black cumin (Nigella sativa L.) variety is an annual herbaceous with a short-life term, that is, particular to the semiarid
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call