Determination of lipid oxidation in sunflower oil treated with several additives

Consumers and food industry are interested in newly developed natural sources of antioxidants to both increase the nutritional value of products and make them healthier. Therefore, the results of this study might be useful for developing novel oil products that are biologically rich, and have a desirable shelf life. Within the scope of the present study, sunflower oil, which is one of the most consumed oils worldwide, was preferred. It was processed by using a hydroxycinnamic acid derivative ( o -coumaric acid) and two popular synthetic antioxidants (tert-butyl hydroquinone and butylated hydroxytoluene). o -coumaric acid increased the shelf life of the oil more than four times (40 days versus 163 days), whereas a synthetic additive increased the shelf life of the oil three times depending on the Rancimat accelerated oxidation test. In terms of bioactive properties such as total phenolic and antioxidant activity values measured by three in vitro tests (ABTS, DPPH, and CUPRAC), each additive contributed (~1.5 times) to the oil significantly different at p < 0.001. A negative value for entropy (Δ S ++ < 0) was calculated, confirming the nonspontaneous reaction (Δ G ++ > 0) with a positive enthalpy (endothermic). Graphical abstract