Quality of oil extracted by cold press from Nigella sativa seeds incorporated with rosemary extracts and pretreated by microwaves

Abstract

Black cumin (Nigella sativa) seed (BS) oil has high a peroxide value (PV) and acid value (AV). In this study, BS was incorporated with different levels of rosemary extracts as a natural antioxidant source before and after pretreatment by microwaves. Based on the oil extraction yield (33%), PV (8.4 meq O2 per kg oil), and AV (3.2 mg KOH per gram oil), the optimum condition was determined as microwave radiation for 120 s and, after that, moisturizing by the extract at 4% level. AV and PV were lower, and chlorophylls, carotenoids, polyphenols, thymoquinone, and tocopherols content were higher in oil extracted from pretreated BS than oil extracted from control BS. Reduction and loss of bioactive components occurred in oil samples during the 120 days of storage; however, it was higher in the control sample. There were no significant differences (p < 0.05) in the fatty acid composition of oil samples; however, oxidation and reduction of linoleic acid in the control oil sample were higher (4.2%) than the oil extracted from pretreated BS (2.5%). In conclusion, the oil extracted from the pretreated BS had higher oil extraction yield, high bioactive components, and stability; therefore, microwave radiation and incorporation of rosemary extract before oil extraction from BS is suggested.

Changes in the quality of oil extracted by hot pressing from black cumin (Nigella sativa) seeds and by solvent from the obtained cake during refining

“…The yield of BCS oil extracted from the two steps described above was determined as follows (Ashrafi et al., 2023):…”

Quality improvement of oil extracted from flaxseeds (Linum usitatissimum L.) incorporated with olive leaves by cold press

“…There have been reports on the effect of olive leaves on the improvement of induction period of sunflower and sesame oils, which were extracted via simultaneous extraction by pressurized propane (Jaski et al, 2022(Jaski et al, , 2023. There are also reports that using rosemary and green tea incorporated with oilseeds while oil extraction by cold press could increase the oxidative stability of extracted oils (Ashrafi et al, 2023;Mikołajczak et al, 2021).…”

Enhancing Oxidative Stability of Nigella Sativa Oil with Some Agro-Industrial Wastes Extracts and its Utilization in Mayonnaise

“…Fatty acid composition affected by seed quality, environmental conditions, and oil-processing technique. Ashrafi et al (2023), stated that it has a high concentration of linoleic acid as olive oil which is one of the three essential fatty acids for human nutrition and can reduce total cholesterol and the low density of lipoproteins. Therefore, antioxidants must be added to avoid and reduce their oxidation and loss during storage.…”

“…Phenolic compounds have antioxidants, prebiotic, antibacterial, antiviral, anti-inflammatory and anticancer effects (Leyva-López et al, 2020). Recently, there has been a focus on the antioxidative application of the active plant materials to control and reduce oxidation in food lipids as well as a trend towards replacing synthetic antioxidants with natural ones that may have health benefits (Uzombah, 2021 andAshrafi et al, 2023). The addition of black seed to mayonnaise may reduce oxidation, enhance flavour, and extend shelf life.…”