Inhibitory Effect of β-Carotene on Lipid Oxidation in Pickering Emulsion

In order to investigate the inhibitory effect of β-carotene on lipid oxidation in Pickering emulsion, the Pickering emulsions embedded with β-carotene were prepared using cellulose nanocrystal (CNC) as an emulsifier. The DPPH and ABTS⁺ radical scavenging rates were used as evaluation indices to examine the antioxidant properties of β-carotene, both before and after embedding. The oxidative and coloring stability of the embedded β-carotene emulsions was investigated by measuring the β-carotene embedding and retention rate, peroxide value (POV), thiobarbituric acid (TBA) value, and color difference. The results showed that the β-carotene embedded in the emulsions had a good scavenging effect on DPPH and ABTS⁺ free radicals. The retention of β-carotene in the emulsions significantly decreased (P<0.05) due to the free radical scavenging and auto-oxidation reactions of β-carotene. There was a highly significant negative correlation between the retention of β-carotene and the TBA value in the emulsions (P<0.01). During the accelerated oxidation, the peroxide value (POV) and thiobarbituric acid (TBA) value in the emulsions decreased significantly with increasing β-carotene concentration (P<0.05), and the oxidative stability of the emulsions was significantly improved. This result was because the β-carotene in the emulsion inhibited lipid oxidation by scavenging free radical and auto-oxidation reaction. The color saturation of the embedded β-carotene emulsions significantly increased (P<0.05), and the emulsions had a bright yellow color. Therefore, the oxidative and coloring stability of Pickering emulsions can be enhanced by embedding fat-soluble β-carotene into the emulsions. This advancement broadens the potential applications of Pickering emulsions in fat substitution, nutrient embedding, and nutrient delivery areas.