Influence of the Essential Oil of Foeniculum vulgare Mill. on Sunflower Oil during the Deep-frying Process of Chinese Maye.

Sunflower oil (SFO) is faced with serious oxidation problems during the deep-frying of Chinese Maye, and the search for natural antioxidants has become a focus of scientific research due to the potential toxicity of synthetic antioxidants. In the present study, the Foeniculum vulgare Mill. essential oil (FVEO), tert-butylhydroquinone (TBHQ) were added to SFO for a 30 h deep frying experiment and the results showed that FVEO added to sunflower oil at 1 g/kg was similar to that of TBHQ-0.01 g/kg, and FVEO-1.5 g/kg would promote the oxidation of SFO. FVEO to sunflower oil also prominently restrained the decrease of the sensory properties of the fried product, Chinese Maye, including appearance, taste, flavor and overall acceptance by 24.2%, 20.2%, 46.1% and 56.0% (p < 0.01 or p < 0.05), respectively. The results indicated that FVEO could be used as a natural antioxidant to replace TBHQ in the deep-frying process of SFO, but further research is needed on the key antioxidant constituent of FVEO.

Separated from the Essential Oil of Coriandrum sativum L. Leaves, Carvacrol and Limonene Showed Antioxidant Effects in Sunflower Oil under Frying Conditions.

The frying process, a popular cooking technique, is widely used in the food industry around the world for the production of fried foods. Nevertheless, it is always accompanied by potential challenges including lipid peroxidation of vegetable oils. In this study, the influence of the coriander leaves essential oil (CLEO) on the oxidative stability of sunflower oil under frying conditions and the sensory attributes of fried food (Chinese Mahua) during the sensory evaluation were investigated. The results indicated that compared with the control, CLEO at 0.12 g/kg could obviously suppress the increases for the total polar compounds (TPC), thiobarbituric acid (TBA), color, conjugated dienes (CD), conjugated trienes (CT) and viscosity of sunflower oil, and prominently restrain the oxidization procedure of unsaturated fatty acid (UFA). Meanwhile, the decline in the sensory attributes for the Chinese Mahua was significantly inhibited. Furthermore, the study revealed the antioxidant effect of CLEO was mainly attributed to two compounds, carvacrol and limonene, which were separated by the bioassay-guided fractionation. Consequently, CLEO and the two compounds may be employed as potential natural antioxidants to improve the oxidation stability of sunflower oil under frying conditions.