Arrhenius Equation Modeling for the Oxidative Stability Evaluation of Echium Oil Enriched with a Natural Preservative

Abstract

The present study evaluates the oxidative stability of refined echium oil supplemented with Sophora japonica L. extract (200 ppm). Commonly used synthetic antioxidants (butylated hydroxytoluen (BHT), ascorbyl palmitate, and quercetin) are used as reference additives. The plant extract is evaluated to possess better in vitro antioxidant potential than BHT, and comparable to that of quercetin. The degradation kinetics at 6, 25, and 60°C with and without antioxidants is studied, as well as the progress of oil oxidation. The temperature dependence of oxidation is expressed with the Arrhenius equation in addition to reaction rate constant (k) and activation energy (E a) also determined using Arrhenius equation. Enthalpy of activation (H ‡), entropy of activation (S ‡), and Gibb's free energy of activation (G ‡) are calculated according to the Eyring equation. It is established that the rate constant increased with the temperature of storage. The lipid oxidation reactions are established to follow a zero-order kinetic model for peroxide value. The oxidation reaction is determined as exothermic and non-spontaneous. In conclusion, S. japonica extract is evaluated with high antioxidant potential and can be used as a promising oil stabilizer. It can successfully be added to prevent lipid structure oxidation while providing health benefits to consumers. Practical Applications: The application of natural antioxidants in edible oils in order to substitute synthetic additives is a matter of research interest. The present study aims to compare commonly used synthetic antioxidants with natural ones. Ascorbyl palmitate has the greatest ability to stabilize echium oil at 6, 25, and 60°C, but the Sophora japonica L. extract possesses good potential for retarding the oxidation. The results of this study outline the potential of the natural extract of S. japonica, which needs to be further studied.

Oxidative Stability of Oil Obtained from a Low‐Erucic Acid Pennycress (Thlaspi arvense L.) Mutant with Potential for Food Use

“…Based on the plot, the pre‐exponential factor was 2.78 × 10 10 , similar to other oils. [ 24 ] The activation energy was estimated as 68 kJ mol −1 . The limited sample amounts only allowed for storage experiments at three temperatures, and thus more work is needed to confirm the data with a larger sample set.…”

“…[ 16,28 ] Echium oil, an ω‐3 fatty acid‐rich plant oil, was also found to have a lower activation energy (≈48 kJ mol −1 ) than fae1‐rod1 pennycress oil. [ 24 ] In contrast, bulk oil from rapeseed had a higher activation energy (84.9 kJ mol −1 ). [ 25 ]…”

“…[17] When stored at 40 and 50 °C, oil reached a PV of 15 in 21 and less than 12 days, respectively, while oil stored at 30 °C had not yet reached this value at the end of the storage test. Pseudozero and first order models were explored to fit the increase in PV over storage time as some studies on plant oils found better fits for PV accummulation with a pseudo-zero model, [24,25] others with a pseudo-first order model. [15,16] For fae1-rod1 pennycress oil, pseudo zero order models yielded poor fits, with coefficients of determination of 0.5583, 0.4879, and 0.8523 for the data sets from oils stored at 30, 40, and 50 °C, respectively.…”

“…In contrast, pseudo-first order kinetics fit the data well at 30 and 50 °C (Table 2) and the determination coefficients were in the range of other studies. [15,24] Pseudo-first order kinetics were shown to be suitable for modeling PV of oils stored within a certain temperature range and if headspace oxygen is limiting. [15] Deviations from the Arrhenius model are, however, known to occur above a certain temperature range, dependent on the fatty acid composition.…”

Thermodynamic study of canned mince meat and fish in metal cans during 30 months storage

“…Based on obtained thermodynamic parameters exothermic and thermally reversible processes were seen [15]. Investigation of oxidative stability for echium oil supplemented with SJL extract was presented from Mihaylova et al [16]. Enthalpy of activation (ΔH ‡ ), entropy of activation (ΔS ‡ ), and Gibbs free energy of activation (ΔG ‡ ) were calculated.…”