Structural characterization and oxidative stability of black cumin oil oleogels prepared with natural waxes

Abstract

In this study, black cumin oil (BCO) oleogel was produced using natural waxes (beeswax: BW, sunflower wax: SFW, and carnauba wax: CW) to offer a healthy alternative to shortening. Oiling-off was observed only in the BW oleogel (3.88 ± 0.02%).The CW oleogel had the lowest E a (354.82 kJ/mol), indicating greater resistance to thermal degradation. The highest G′ and G″ were observed in the CW oleogel, while the lowest was observed in the BW oleogel. All oleogel samples displayed weak gel properties (tan δ > 0.1), but the lowest tan δ value belonged to the CW oleogel (0.12).After 4 weeks of storage, the peroxide values of the oleogels were lower than those of bulk oil (p < .05). Finally, the oxidation results showed that the BCO structuring by the waxes effectively protected it from oxidation over eight weeks of storage. Novelty impact statement:The most important innovation of the present study was to investigate the effect of BCO oleogelation on the stability of thymoquinone, the main phenolic compound of BCO. The BCO oleogels had higher thymoquinone content during the first half of the storage period compared with bulk BCO, showing that the oleogel network provides a protective effect against oxidation and thermal degradation.

Comparative analysis of essential oil oleogels containing beeswax and sunflower wax with petrolatum gels

“…Consistent with our own findings, they also observed that the PVs of those oleogel samples increased over time during storage. [22] Gravelle et al [34] reported that oil type and oleogel preparation procedure had a significant effect on the oxidative stability of oleogels. These differences can be explained with the findings of the study conducted by Gravelle et al [34] The delta E value is an important quality criterion and is defined as the change in color during storage.…”

“…Additionally, the SW-and BW-based gels had a higher T m when compared to the control group samples. Orhan and Ero glu [22] reported that oleogels prepared with BCO and 10%-BW and 7%-SW had endothermic peaks at 53 and 64 • C, respectively. Yi et al [20] reported that the crystallization onset (T on ) and peak temperatures (T c ) of GSO oleogels containing 15% BW were 21.73 and 20.45 • C, whereas their melting onset and T m were 24.11 and 40.52 • C, respectively.…”

“…On the other hand, the highest increase was observed both BW-and S1). Orhan and Ero glu [22] reported that BCO and 10%-BWand 7%-SW-based oleogels were 226.38 and 520.88 g, respectively.…”

“…However, the literature data reported different findings for oleogels prepared with different oils and waxes. [ 20,22,32,33 ] According to Öğütcü et al., [ 32 ] the PVs of cod liver oil oleogels based on BW were lower than those of carnauba oleogels after 90 days of storage (20°C). Yi et al.…”

“…[ 20 ] and Choi et al. [ 21 ] Recently, Orhan and Eroğlu [ 22 ] reported the common characteristic of black cumin‐beeswax (BW) oleogels. There is very limited information in the literature on EO oleogels and their potential applications.…”