Quality Changes of Cold-Pressed Black Cumin (Nigella sativa L.), Safflower (Carthamus tinctorius L.), and Milk Thistle (Silybum marianum L.) Seed Oils during Storage

Abstract

Oils derived from non-traditional seeds, such as safflower, milk thistle, and black cumin seeds, have recently grown in popularity. Seed oil is in high demand due to consumer interest in illness prevention and health promotion through healthier diets that include a high concentration of monounsaturated and polyunsaturated fatty acids and antioxidant phenolic components. This study assessed the quality characteristics of cold-pressed seed oil at three unique storage times: at the beginning of the trial (i.e., before storage), after 2 months, and after 4 months. The results of the performed analyses indicate that the acidity of extracted black cumin, safflower, and milk thistle seed oil fluctuates considerably over time. The highest acidity level change was detected for black cumin seed oil, from 10.26% after the extraction to 16.96% after 4 months of storage at 4 °C. Consequently, changes between pre- and post-storage peroxide concentrations were discernible after four months. Peroxide value in milk thistle and safflower seed oils increased by 0.92 meq/kg and 2.00 meq/kg, respectively, during the assessed storage time, while that of black cumin was very high and fluctuated. The storage period substantially affects oxidative changes and the oxidation stability of the oil. Major changes were observed in the polyunsaturated fatty acids in seed oil during storage. The essential changes were detected in the black cumin seed oil odor profile after 4 storage months. Their quality and stability, as well as the nature of the changes that occur during the storage of oil, require extensive investigation.

Variation in the Composition and Quality of Nigella sativa L. Seed Oils—The Underestimated Impact on Possible Health-Promoting Properties

“…23% α-linolenic acid, total polyunsaturated fatty acids approx. 15%, or ca 13% of trans -9-elaidic acid) are exceptional cases [ 2 , 19 , 29 ] and probably misleading samples.…”

Essential Components from Plant Source Oils: A Review on Extraction, Detection, Identification, and Quantification

“…Cold-press extraction is a cost-effective, green, and safe extraction technique, providing pure and nutritionally rich oils but the comparatively less net yield is a drawback [180].…”

Optimization and Validation of Sensitive UPLC-PDA Method for Simultaneous Determination of Thymoquinone and Glibenclamide in SNEDDs Formulations Using Response Surface Methodology

“…Nigella sativa plant contains variable amounts of phytochemicals that produce different beneficial effects on the quality of life [5]. Thymoquinone (TQ) is a well-known active substance that exerts different pharmacological effects including antidiabetic effects.…”