Evaluation of antioxidant properties of Za’atar (Thymbra spicata) essential oils as natural antioxidant for stability of palm olein during deep-fat frying process

Abstract

The yield of Za'atar () essential oils were found to be 2.5-3.4% at extraction process temperatures of 100-175 °C. The essential oils contained 79.5-86.2% carvacrol. Effects of BHT and Za'atar essential oil on stability of palm olein during deep-fat frying of potato slices were studied at 180 °C. Changes in peroxide, para-anisidine, iodine values, free fatty acid and color were determined. Za'atar essential oil and BHT reduced free fatty acid content of olein from 0.27 to 0.21% (oleic acid) after 50 frying cycles. Antioxidant addition did not change the peroxide value of oil. Frying decreased Hunter value and increased, , and total color difference values of used oils. The-anisidine value changed from 15 to 33 for control oil during frying. BHT and Za'atar essential oil reduced this value to 28. The iodine values of olein reduced from an initial value of 54.5 to 45, 49 and 49 for control, BHT and Za'atar essential oil added frying oils, respectively. Za'atar essential oils could be used for preserving palm olein during deep-fat frying process.

The variation of oxidative stability and sensory attributes of sunflower oil induced by essential oil from Magnolia liliflora Desr. during high‐temperature storage

“…The values for AV, PV, q-AnV and TOTOX of control group significantly increased À1 , 5.43 and 195.63, respectively. Furthermore, the results also indicated that the addition of MLEO at 1600 mg kg À1 in sunflower oil was able to inhibit the development of free fatty acids, primary and secondary oxidation products, which was in agreement with the several previous studies (Maskan, & Horuz, 2017;Chandran et al, 2017).…”

“…For instance, at 1600 ppm, the addition of lemonverbena essential oil to sunflower oil could enhance the oxidative stability of sunflower oil and retard its lipid oxidation (Farahmandfar et al, 2018). Maskan & Horuz (2017) demonstrated that Za'atar (Thymbra spicata) was able to restrain the oxidative degradation of palm olein during frying process by means of its essential oil. Quite interestingly, essential oils not only increase the antioxidant activity of vegetable oils, but also improve the sensory properties and consumers' acceptability of them by its flavour characteristics (Chandran et al, 2017).…”

Antioxidant Activity and Sensory Improvement of Angelica dahurica cv. Yubaizhi Essential Oil on Sunflower Oil during High-temperature Storage

“…Quite interestingly, the synergistic effect of ADEO and TBHQ in inhibiting the oxidation of sunflower oil was perfectly demonstrated. Recently, the essential oil from Teucrium polium was demonstrated to suppress the changes for AV and PV during the storage of canola oil, and the essential oil of Thymbra spicata was found to suppress the alteration of PV and AnV in the deep-fat frying procedure of palm olein [29,30]. The results were in conformity with these reports.…”

Composition, and antioxidant and enzyme‐inhibition activities, of essential oils from Satureja thymbra and Thymbra spicata var. spicata

“…The essential oils of T. spicata were used as natural antioxidants to stabilize palm oil during deep‐fat frying and in Turkish dry‐fermented sausage . The essential oils of S. thymbra are active antioxidants in the carotene–linoleic acid system, prevent the Cu 2+ ‐mediated oxidation of low‐density lipoprotein (LDL), and show activity in 2,2‐azino‐bis (3‐ethylbenzothiazloine‐6‐sulphonic acid) radical cation (ABTS) and 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) assays …”