Antioxidant potential of Camellia tetracocca and meitan turquoise bud in inhibiting oxidative degradation of edible oils

Effective antioxidants are crucial for preventing lipid deterioration. This study aimed to investigate the antioxidant properties and inhibitory effect on lipid oxidation of Camellia tetracocca (CT) and Meitan Turquoise Bud (MTB) extracts. The research analyzed the total flavonoids, phenolics, and major components content of the extracts. Additionally, it evaluated the in vitro antioxidant ability (FRAP, DPPH, ABTS assays) and lipid peroxidation inhibitory activity, and calculated the binding energy of the major components and fatty acids. Compared to CT, MTB had higher total flavonoid and phenolic content, along with superior antioxidant activity in vitro. Both extracts effectively inhibited the increase of POV in camphor oil and olive oil containing 74.63% and 69.96% oleic acid, respectively. Interestingly, MTB outperformed CT twelve days earlier, but CT surpassed MTB twelve days later in inhibition rates on these oils. Molecular docking confirmed that the binding energy of the active ingredients in both extracts with oleic acid-type edible oil is higher than that with linoleic and linolenic acid types. These findings indicate that CT and MTB extracts are promising natural antioxidants for oleic acid-rich edible oils. Given their differing impact on the oxidation rate of edible oil, using both extracts together may produce superior outcomes.