Antioxidant Activity of Rosemary Extract in Soybean Oil Under Thermoxidation

Abstract

This study examined the antioxidant activity of lyophilized rosemary extract added to soybean oil, subjected to thermoxidation conditions and also its synergistic effect with the synthetic antioxidant tertiary butylhydroquinone (TBHQ). Soybean oil samples with no antioxidant added (SO), 3,000 mg/kg rosemary extract (RE), 50 mg/kg TBHQ (TBHQ), and a mixture of those two antioxidants (RE + TBHQ) were heated to 180C for 20 h. After 0, 10 and 20 h, the oxidative stability, total polar compounds, tocopherol content and fatty acid profile were determined. The addition of rosemary extract increased oxidative stability and resulted in a lower formation of total polar compounds and a higher retention of tocopherols. The RE treatment showed the highest amount of polyunsaturated fatty acids after 20 h. There was not any synergy between TBHQ and rosemary extract in preventing oxidation of soybean oil. Rosemary extract showed a higher antioxidant potential when compared with TBHQ. PRACTICAL APPLICATIONS Antioxidants are important ingredients in food processing because they have the capacity to protect foods, containing oils and fats, from damage caused by free radicals and reactive oxygen species. Synthetic antioxidants are widely used in the food industry; however, their utilization has been questioned because of toxicity. Therefore, there is a growing interest in the use of natural antioxidants to reduce or replace the synthetic antioxidants. Several species are used in cooking, medicine and by the pharmaceutical industry, standing out the rosemary. Being rich in compounds with high antioxidant activity, the rosemary extract can be used to replace synthetic antioxidants used in vegetable oils.

Thiamine losses during storage of pasteurised and sterilized model systems of minced chicken meat with addition of fresh and oxidized fat, and antioxidants

“…The protective effect of rosemary extract to thiamine, that was demonstrated in the study, can be explained by its antioxidant properties. The inhibition of lipid oxidation by rosemary extract was previously proved Dolata 2007, Casarotti andJorge 2012]. However, the results of our study demonstrated that casein hydrolysate had higher protective effect to thiamine than rosemary extract in stored meat samples with high-oxidised fats.…”

Influence of Tunisian aromatic plants on the prevention of oxidation in soybean oil under heating and frying conditions

“…Inhibition of polar compounds formation in frying oil supplemented with natural antioxidant from herbs or plants has also been reported in other studies (Casarotti & Jorge, 2014;Nor et al, 2009;Urbancic et al, 2013).The increase of PC in the control oil during heating was the result of a faster rate of oxidation and thermal reactions during heating (Zhang et al, 2012).…”

Evaluation of antioxidant activity of loquat fruit (Eriobotrya japonica lindl.) skin and the feasibility of their application to improve the oxidative stability of soybean oil

“…Therefore, the low levels of both conjugated dienes and trienes in SOEA are indications of good oxidative stability of the oil. The conjugated dienes and trienes results are approved by other studies such as Casarotti and Jorge (2014) and Urbančič et al (2014), that showed the antioxidant effect of rosemary extract in prevention of conjugated compounds augmentation in vegetable oil was higher than TBHQ. During storage conditions the CDV and CTV values ( Fig.…”