Abstract: This study investigated the changes of natural pigments and volatile components in sunflower oil during the refining process. A high performance liquid chromatography (HPLC) method was established and optimized for the detection of natural carotenoids and flavonoids pigments in sunflower oil during the refining process (crude, deacidified, dewaxed, decolorized and deodorized oil). The results showed that the content of natural carotenoids in the crude oil was in the following order: lutein (1.44 μg/g) > β-carotene (0.55 μg/g) > zeaxanthin (0.51 μg/g) > lycopene (undetectable). The content of flavonoids was in the following order: fisetin (2.60 μg/g) > kaempferol (2.06 μg/g) > quercetin (2.00 μg/g) > isoquercitrin (1.58 μg/g) > luteolin (1.21 μg/g). In addition, the decolorization process was responsible for the loss of carotenoids and the deacidification process was responsible for the loss of flavonoids. Totally 264 volatile components were identified in sunflower oil, the dominant ones being terpenes and aldehydes, and the deodorization process had a significant effect on aroma components of sunflower oil, reducing the contents of terpenes, aldehydes, and alcohols by 99.27%, 81.10%, and 94.75%, respectively. The refining process decreased the antioxidant activity of sunflower oil, which may be attributed to the loss of natural pigments. This study provides a scientific basis for optimizing the traditional refining process of sunflower oil and improving its quality and nutritional value.

Key words: sunflower oil; pigments; volatile components; antioxidant capacity; refining process