مجله پژوهشهای علوم و صنایع غذایی ایران (Nov 2024)
Effects of Lavender Essential Oil Addition on Oxidative Stability of Canola Oil under Accelerated Condition
Abstract
Introduction Canola oil with high unsaturated fatty acids and nutritional value is susceptible to oxidation due to lipid oxidation. Lipid oxidation leads to a reduction of nutritional quality, sensory and safety characteristics of the vegetable oils. To retard lipid oxidation, the synthetic antioxidants are usually used in the vegetable oils. By increasing the public concern about health problems of synthetic antioxidants, the use of natural antioxidants is increasing. Lavender (Lavandula officinalis) is an evergreen plant native to the Mediterranean. The presence of linalool, linalyl acetate, 1,8-cineole B-ocimene, terpinen-4-ol, and camphor in lavender essential oil, make it a good natural antioxidant which could use in food industry. Therefore, in the current research, it was aimed to investigate the antioxidant effect of lavender essential oil on the stability of canola oil. Material and Method The lavender was bought from Golestan province and dried in room temperature. The lavender essential oil was prepared by hydro distillation of flower heads. Then, the phenolic compounds were determined using GC-MASS. The Total phenolic content (TPC), flavonoid content (TFC), and antioxidant activity (FRAP and DPPH) of lavender essential oil were evaluated. Then, lavender essential oil in concentrations of 200, 400, 600, 800, and 1000 mg/kg was added to the crude canola oil compared to canola oils without antioxidants and synthetic antioxidant TBHQ (100 and 200 mg/kg). Then, the samples were kept at 60 to 70 oC for 12 days. The analysis was done in an interval of 24 h for 12 days. Lipid oxidation of samples was determined by peroxide value, p-anisidine value, TOTOX value, and thiobarbituric acid each 24 h. analyses of Data were done by one-way analysis of variance (ANOVA) using SPSS software and the means were compared by the Tukey multiple range test. Result and Discussion According to the GC-MS analysis, 1, 8-cineole (59.45 %), linalool acetate (32.48 %), linalool (6.31 %), and limonene (1.06 %) were identified as the major constituent of lavender essential oil. Also, Total phenol, flavonoid, FRAP and DPPH (IC50) contents of lavender essential oil were 71.55 mg GAE/g, 82.66 mg of rutin/100 g, 12.63 mmol H2SO4, and 55.88 mg/ml, respectively. According to the results, all lipid oxidation indexes were increased after twelve days of storage. In general, lavender essential oil was effective in retarding the oxidation of canola oil at a temperature of 70 oC. Also, the concentration of 1000 mg/kg of the essential oil had antioxidant activities similar to the TBHQ in 100 mg/kg concentration. Conclusion It was showed that lavender essential oil, as a natural antioxidant, has the ability to react with the radicals resulting from the oxidation of lipids and causes the interruption of oxidation chain reactions and increases the time and decreases the rate of oxidation. As observed, the oxidation of canola oil in all samples, especially the samples without antioxidants or antioxidants to a lesser extent, increased significantly with increasing storage time. In general, lavender essential oil at L1000 concentration and also in some oxidation indices of lavender essential oil at L800 concentration has an effective role in preventing the oxidation of canola oils like synthetic antioxidant TBHQ.
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