Study of the thermal behavior of rosemary extract and its temperature-related antioxidant effect on chicken fat

The relationship between the thermal behavior and antioxidant stability of rosemary extract (RE) was investigated. Through simultaneous thermal analysis (TG-DTA) and total phenolic content measurement, stability of RE below 200 degrees C and the resistance of phenolics below 130 degrees C have been found, revealing an asynchrony between weight loss and destruction of antioxidant capacity. Peroxide value, p-anisidine value, TG-DTA, Rancimat test, and kinetic analysis of chicken fat at 90-150 degrees C were also carried out to further determine the antioxidant stability of RE on the oxidation and degradation of edible fats. Consequently, the highest antioxidant activity index is 6.49 at 120 degrees C, and RE elevates the initial degradation point of chicken fat under thermal stress by reducing oxygen absorption. Besides, the antioxidant effect of RE is found to be weaker due to the thermal destruction of the phenolics, but a higher temperature below the destruction point can cause a better antioxidant effect. Novelty impact statement The antioxidant effect of RE is related to temperature and the thermal stability of components. The thermal behavior and antioxidant stability of rosemary extract are inconsistent. Rosemary extract shows the best antioxidant effect below the destruction point (130 degrees C) despite the severer oxidation of chicken fat with increasing temperature.